4 Cepaea hortensis. Juvenile. 11.5mm high, 14mm wide. Pennine foothills, V.C. Derbyshire, England. August 2018.

Body whorl 89% of shell height, so spire 11% (smaller % than spire on adults). Aperture 69% of shell height.
1: thin, fragile outer lip lacking any thickening indicates juvenile shell. (This juvenile is as big as some adults; use lip thickness, not size, to decide if a shell is adult or juvenile.)
2: distinct columellar lip, only on juveniles.
3: parietal lip not distinguished by glaze or other feature (but develops on adults) .
4: open umbilicus (sealed on adults).

Cepaea hortensis (O.F.Müller, 1774)
Synonyms: Helix hortensis O.F.Müller, 1774; Helix nemoralis var. hortensis in Jeffreys.
GLOSSARY below.

Body description
External anatomy of extended specimen.
Apart from the smooth sole and ventral surface of the head, the entire exposed body is covered in closely-set, ellipsoid tubercles 9Ch 9 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . Those on the flanks are arranged in approximately longitudinal lines slanting upwards towards the posterior 11Ch 11 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . Translucent greyish white on flanks darkens to brown dorsally with a medial dorsal line of single, colourless, transparent tubercles 11Ch 11 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . Viscera are sometimes indistinctly visible through the body wall 12Ch 12 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. ; the black internal continuation of the ocular tentacles and smaller anterior tentacles especially so. When the ocular tentacle is extended, the eye is positioned on a terminal, spherical bulb 11Ch 11 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . The foot is widest at about half of its length from the head; rounded at the anterior; tapering to a rounded point at the posterior 13Ch 13 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . Sole yellow, darkening to brownish when compressed to adhere strongly to substrate 14Ch 14 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . Pneumostome sometimes visible within shell aperture on right 15Ch 15 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. & 16Ch 16 Cepaea hortensis retracted within shell. Widths 15.7mm and 16mm, Sept.& Aug. 2018 Pennine foothills, V.C. Derbyshire, England. .

Functional internal anatomy:
Muscular system
The largest muscle is the white columellar muscle which connects the columella of the shell to the foot, and is used to draw the animal into the shell. It may be seen when the animal is first extracted from the shell 17Ch 17 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. September 2018. . Many other muscles, such as those retracting the tentacles and buccal mass, run close to and join the columellar muscle; all need to be severed during dissection 18Ch 18 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. if the body is to be straightened out for examination.
The ocular tentacles 19Ch 19 Cepaea hortensis. Nerve ring. Pennine foothills, V.C. Derbyshire, England. August 2018. , and other organs such as anterior tentacles, dart sac and penis 20Ch 20 Cepaea hortensis penis. Pennine foothills, V.C. Derbyshire, England. September 2018. are withdrawn into the body by the pull of retractor muscles that invert the organs like a sock pulled outside in 18Ch 18 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . They are everted out of the body by muscles increasing the hydrostatic pressure in them of the haemolymph (invertebrate blood) which occupies the haemocoel (body cavity) free of confinement by veins or arteries.
Respiratory system
The mantle cavity is sealed by a yellowish collar of thickened mantle that has a pneumostome (respiratory pore) which can be opened for inhalation/exhalation of air 15Ch 15 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. & 16Ch 16 Cepaea hortensis retracted within shell. Widths 15.7mm and 16mm, Sept.& Aug. 2018 Pennine foothills, V.C. Derbyshire, England. or closed to seal the cavity against dehydration. The transparent, sometimes spotted, roof of the mantle cavity contains a network of blood vessels 21Ch 21 Cepaea hortensis mantle. Pennine foothills, V.C. Derbyshire, England. August 2018. and is very thin, enabling oxygen from inhaled air to diffuse into the vessels and for carbon dioxide to leave with the exhaled air. Air is moved in and out of the mantle cavity by the snail lowering and raising the floor of the mantle cavity 22Ch 22 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. to reduce or increase the air pressure in the cavity relative to that of the atmosphere. The oxygenated blood (haemolymph) is circulated to the rest of the body by the heart near the mantle cavity 22Ch 22 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . Colourless haemolymph, depleted of oxygen, returns to the vascular roof of the mantle cavity via capillary vessels.
Alimentary system
The mouth is a transverse slit from which a radula emerges to rasp and gather food particles into the buccal cavity 23Ch 23 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . The radula is a broad chitinous band covered with thousands of white teeth arranged in transverse rows 24Ch 24 Cepaea hortensis. Radula and radula sac. Pennine foothills, V.C. Derbyshire, England. August 2018. . It is created within a white radula sac which is folded at the posterior where it protrudes from the rear of the buccal mass 25Ch 25 Cepaea hortensis. Radula and radula sac. Pennine foothills, V.C. Derbyshire, England. August 2018. . The radula rests on a pair of cartilaginous bolsters 26Ch 26 Cepaea hortensis. Nerve ring. Pennine foothills, V.C. Derbyshire, England. September 2018. , the odontophore, which support it as it is thrust back and forth. At its anterior, the radula emerges from the sac and flattens in readiness for use. A static red jaw with strong ribs is set into the top of the mouth 27Ch 27 Cepaea hortensis. Radula and jaw. Pennine foothills, V.C. Derbyshire, England. August 2018. ; it retains food loosened by the radula. Copious saliva to assist ingestion is brought to the buccal cavity and mouth from salivary glands by long salivary ducts 28Ch 28 Cepaea hortensis. Alimentary system. Pennine foothills, V.C. Derbyshire, England. August 2018. . The short anterior tentacles, which can be retracted by inversion, are close to the mouth 29Ch 29 Cepaea hortensis heads. Pennine foothills, V.C. Derbyshire, England. August 2018. . When not feeding, the mouth is concealed behind a pair of lobe-like lips that open laterally, and the lips are flanked by lobes of the head 29Ch 29 Cepaea hortensis heads. Pennine foothills, V.C. Derbyshire, England. August 2018. . The buccal cavity leads to the oesophagus and subsequently to a wider, long, capacious crop alongside of which the large salivary glands are located 28Ch 28 Cepaea hortensis. Alimentary system. Pennine foothills, V.C. Derbyshire, England. August 2018. . The crop leads to the narrower intestine which loops through the digestive gland 18Ch 18 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. , where digestion takes place, before joining the rectum along the right side of the body 28Ch 28 Cepaea hortensis. Alimentary system. Pennine foothills, V.C. Derbyshire, England. August 2018. and ending at the anus which defecates into the mantle cavity. Conservation of water is important for land molluscs such as C. hortensis so faeces are quite dry 30Ch 30 Cepaea hortensis faeces. Pennine foothills, V.C. Derbyshire, England. September 2018. . Faeces and excreta leave the mantle cavity with the exhalent current out of the pneumostome.
Nervous system
Instead of a single brain C. hortensis, like other gastropods, has a series of ganglia (nerve knots) on a nerve cord that runs in a ring around the oesophagus 19Ch 19 Cepaea hortensis. Nerve ring. Pennine foothills, V.C. Derbyshire, England. August 2018. with a dorsal and a ventral longitudinal extension towards the posterior on each side of the body 31Ch 31 Cepaea hortensis nerve cords. Pennine foothills, V.C. Derbyshire, England. September 2018. . Each ganglion innervates a, usually proximate, specific part of the body. The cerebral ganglia on the nerve ring connect 32Ch 32 Cepaea hortensis nerve cords. Pennine foothills, V.C. Derbyshire, England. August 2018. to the ocular tentacles, eyes and other parts of the head such as a subsidiary ring with ganglia around the buccal mass 26Ch 26 Cepaea hortensis. Nerve ring. Pennine foothills, V.C. Derbyshire, England. September 2018. to control its feeding movements. The pedal ganglia on the ventral part of the nerve ring connect to the foot, and other regions of the body are connected to ganglia on the longitudinal extensions towards the posterior.
Reproductive system
[This section is based on Kerney & Cameron (1979) and Cameron (2008) except the part in italics which is based on Lodi & Koene (2016). The functions of love darts, the bursa copulatrix and diverticulum are not fully understood; some different hypotheses are mentioned below image 36Ch 36 Cepaea hortensis. Dissection with reproductive organs isolated and spread out. Pennine foothills, V.C. Derbyshire, England. September 2018. .]
C. hortensis is a simultaneous hermaphrodite. A mating couple approach each other face to face and try to manoeuvre into position to shoot a sharp dart of crystalline calcium carbonate 33Ch 33 Cepaea hortensis, love dart. Pennine foothills, V.C. Derbyshire, England. September 2018. & upload.wikimedia.org/wikipedia/commons/8/8e/Cepaea_horten… into the body wall of the other by forceful eversion of its containing dart sac 34Ch 34 Cepaea hortensis. Dissection with mantle and body wall removed; organs as uncovered, undisturbed. Pennine foothills, V.C. Derbyshire, England. September 2018. . The dart is coated with mucus from a pair of 4-branched (sometimes 5-branched) mucus glands 34Ch 34 Cepaea hortensis. Dissection with mantle and body wall removed; organs as uncovered, undisturbed. Pennine foothills, V.C. Derbyshire, England. September 2018. & 35Ch 35 Cepaea hortensis. Dissection with reproductive organs isolated and spread out. Pennine foothills, V.C. Derbyshire, England. September 2018. connected close to the opening of the dart sac. The penis 20Ch 20 Cepaea hortensis penis. Pennine foothills, V.C. Derbyshire, England. September 2018. of each is everted, like a sock turned inside out, through the atrium and out of the genital pore by hydrostatic pressure of haemolymph (blood). Each inserts its penis through the other’s genital pore and atrium into its vagina 35Ch 35 Cepaea hortensis. Dissection with reproductive organs isolated and spread out. Pennine foothills, V.C. Derbyshire, England. September 2018. .
[The following two paragraphs are best understood if read from the caption below image 36Ch 36 Cepaea hortensis. Dissection with reproductive organs isolated and spread out. Pennine foothills, V.C. Derbyshire, England. September 2018. as numbers (1) to (17) refer to features in the image.]
Spermatozoa travel from the ovotestis (1) through the common duct (2 a.k.a. ovotestis duct or little hermaphrodite duct) to the albumen gland (3), thence through the prostate gland (4) and vas deferens (5) to the penis (6) where they are formed by its epiphallus (6e) and flagellum (6f) into a spermatophore (long thin package). The spermatophore is ejected through the everted penis into the other snail’s vagina (7) 37Ch 37 Cepaea hortensis. Dissection with reproductive organs isolated but not spread out. Pennine foothills, V.C. Derbyshire, England. September 2018. . Fertilization is delayed for a few weeks, sometimes months, while a store of allosperm is accumulated in the diverticulum from couplings with other partners. To try to ensure that a single partner’s sperm does not monopolize the fertilization, each allosperm deposit is reduced by the bursa copulatrix (8) digesting some of it on its transit from the vagina along the bursal duct (9) towards the diverticulum (10 small on this species). The insertion of a love dart from its sac (11) by the sperm-inserting partner earlier in the mating process partially counters the reduction of its allosperm contribution as the dart is coated from the mucus glands (12) with mucus containing chemicals that cause contraction waves in the vagina (7) which intermittently constrict the duct branch (13) to the bursa copulatrix (8), and increase the contractions of the diverticulum (10) which probably ease the passage of the spermatophore into it. Allosperm are stored in the diverticulum until required.
Ova pass from the ovotestis (1) through the common duct (2 a.k.a. ovotestis duct) to the albumen gland (3) 38Ch 38 Cepaea hortensis. Dissection of part of reproductive organs. Pennine foothills, V.C. Derbyshire, England. September 2018. where they each receive a coating of nutrient albumen and move into the fertilization chamber (14). Stored allosperm are released to swim down the bursal duct (9) and up the oviduct (15) 37Ch 37 Cepaea hortensis. Dissection with reproductive organs isolated but not spread out. Pennine foothills, V.C. Derbyshire, England. September 2018. to fertilize the ova in the fertilization chamber. The fertilized ova then travel down the oviduct, through the atrium (16), and out of the genital pore (17) to be laid in a cavity excavated in the soil. Hatching occurs after some weeks; the period depending on temperature and humidity. Crawling miniature adults emerge as there is no larval stage.

Key identification features

Cepaea hortensis
Features in common with C. nemoralis (Linnaeus, 1758)
1. No umbilicus on adults 3Ch 3 Cepaea hortensis. 11.5mm high X 16mm wide. Pennine foothills, V.C. Derbyshire, England. August 2018. , but present on some juveniles 4Ch 4 Cepaea hortensis. Juvenile. 11.5mm high, 14mm wide. Pennine foothills, V.C. Derbyshire, England. August 2018. .
2. On adults, outer lip of aperture rounded in its upper part, turning sharply into a straight basal part. Juveniles differ. 2Ch 2 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. .
Feature frequent on Cepaea hortensis, but sometimes on C. nemoralis
3. On adults, outer lip of aperture has a white thickening and rib just within the rim 6Ch 6 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. September 2018. & 5Ch 5 Cepaea hortensis. 13.3mm high X 17,5mm wide. Pennine foothills, V.C. Derbyshire, England. September 2018. . Externally, brown pigment bands do not extend onto the rim of the lip; it is usually pale yellow. Lips on juveniles of both Cepaea spp. lack thickening, rib and colour distinction 2Ch 2 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . Care is needed not to mistake the pale mantle for a pale lip when sometimes reflected over and concealing the outer lip.
4. The red jaw has 2 to 4 strong ribs is set into the top of the mouth 27Ch 27 Cepaea hortensis. Radula and jaw. Pennine foothills, V.C. Derbyshire, England. August 2018. (Number has overlap with C. nemoralis which has 4 to 7 ribs.)
Reliable diagnostic features that differentiate C. hortensis from C. nemoralis
5. The love dart has four vanes that are thin at base and thicker and bifurcated distally, giving a cross section like a Maltese cross 33Ch 33 Cepaea hortensis, love dart. Pennine foothills, V.C. Derbyshire, England. September 2018. . But, the dart is very brittle and often missing. For examination, a stereoscopic dissecting microscope at c.X20 is needed.
6. A pair of 4-branched (occasionally 5-branched) mucus glands are connected close to the opening of the dart sac 34Ch 34 Cepaea hortensis. Dissection with mantle and body wall removed; organs as uncovered, undisturbed. Pennine foothills, V.C. Derbyshire, England. September 2018. & 35Ch 35 Cepaea hortensis. Dissection with reproductive organs isolated and spread out. Pennine foothills, V.C. Derbyshire, England. September 2018. .

Similar species

Cepaea nemoralis
1. As 1 above for C. hortensis.
2. As 2 above for C. hortensis.
3. On adults, outer lip of aperture usually has a brown thickening and rib just within the rim 45Ch 45 Cepaea hortensis album. COMPARISON images of C. nemoralis with typical brown lip. Pennine foothills, V.C. Derbyshire, England. August 2018. . But white lipped specimens occur 46Ch 46 Cepaea hortensis album. COMPARISON images of C. nemoralis with atypical white lip. Top line: Pennine foothills, V.C. Derbyshire, Aug. 2018. Lower line: Lowland Cheshire, England, March, 2001. . Lips on juveniles of both Cepaea spp. lack thickening, rib and colour distinction. Care is needed not to mistake the pale mantle for a pale lip when sometimes reflected over and concealing the outer lip.
4. The red jaw has 4 to 7 strong ribs (Hudson in Topley, 2006). Number has overlap with C. nemoralis which has 4 to 7 ribs.
5. The love dart has four vanes thickest at base and tapering steadily distally giving a cross section of a simple cross 47Ch 47 Cepaea hortensis album. COMPARISON image of C. nemoralis love dart. Pennine foothills, V.C. Derbyshire, England. August 2018. . But, the dart is very brittle and often missing. For examination, a stereoscopic dissecting microscope at c.X20 is needed.
6. A pair of 2-branched or 3-branched mucus glands are connected close to the opening of the dart sac 48Ch 48 Cepaea hortensis album. COMPARISON dissection of C. nemoralis reproductive organs. Pennine foothills, V.C. Derbyshire, England. August 2018. . (In a Croatian study, two specimens with C. nemoralis type love darts had 4-branched glands (Štamol & Slapnik, 2015)).
7. maximum diameter 24mm, so Cepaea with diameter greater than 20mm (max. for C. hortensis) are most probably C. nemoralis 46Ch 46 Cepaea hortensis album. COMPARISON images of C. nemoralis with atypical white lip. Top line: Pennine foothills, V.C. Derbyshire, Aug. 2018. Lower line: Lowland Cheshire, England, March, 2001. . In mixed populations, C. nemoralis is usually obviously larger than C. hortensis.
Comment:
Relying for identification of a single specimen solely upon the feature suggested by the vernacular names "White-lipped snail" (C. hortensis) and "Brown-lipped snail" (C. nemoralis) can lead to misidentification. In areas where a species has not been previously recorded, several specimens should be examined and the mucus gland and love dart dissected before submitting the record to a recording scheme. The Pennine specimens illustrated in this account come from a garden where for 35 years C. hortensis was common, but C. nemoralis not seen until the hot dry summer of 2018 when 9 adults were found; 8 with brown lips and one with a white lip (love darts and mucus glands examined).
Special care is needed in continental Europe where further similar species occur. On the basis of lip colour, C. hortensis was regarded for over 150 years as living in Croatia. Recent fieldwork at its previously recorded sites failed to discover it, but found 6 white-lipped and 2 brown-lipped specimens with darts and mucus glands as described for C. nemoralis, casting doubt on the occurrence of C. hortensis in Croatia and possibly other Balkan areas (Štamol & Slapnik, 2015).
Habits and ecology
In moderately moist, sheltered habitats, including under leaf litter and stones, lush road verges, woods, rocks and gardens. Also on well drained maritime turf and sand dunes in cool, moist Scotland from the Firth of Forth northwards (Boycott, 1934).
The varied colours of the faeces 30Ch 30 Cepaea hortensis faeces. Pennine foothills, V.C. Derbyshire, England. September 2018. reflect the diet of mixed decaying organic detritus and soft living plant material. Feeding action is precisely controlled to maximize use of a food source with minimum effort or waste. On a piece of glass coated with dried flour paste the foot is attached firmly to hold the shell stationary 14Ch 14 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . The head is extended and makes a stroke of the radula to rasp flour to the stationary jaw and into the mouth 23Ch 23 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August 2018. . The head is then moved slightly to the side and a second radula stroke made parallel and immediately adjacent to the first so it does not scrape any of the surface already dealt with, but leaves no waste between strokes except for a small triangle left by the narrowed tip. This is repeated until the head can swing no further. A timed swing of the head accommodated 15 radula strokes and took 23 seconds so each stroke and repositioning took c.1.5 seconds 39Ch 39 Cepaea hortensis feeding on dried flour paste on glass. Pennine foothills, V.C. Derbyshire, England. August 2018. . The animal then advances slightly so the next swing is on new food leaving no waste except a narrow strip containing the triangles formed by the radula tip. In captivity on horizontal glass, the snail shifted periodically to clear a rounded area. An area of paste about equal to the basal area of the snail was cleared every 6 minutes 40Ch 40 Cepaea hortensis feeding on dried flour paste on glass. Pennine foothills, V.C. Derbyshire, England. August 2018. . In the wild the feeding pattern can be seen on alga-coated surfaces, but the area cleared is often linear. This was replicated when the sheet of glass was stood on edge and the snail worked upwards, suggesting that it is negatively geotaxic 41Ch 41 Cepaea hortensis feeding marks on dried flour paste on glass. Pennine foothills, V.C. Derbyshire, England. August 2018. . However, observations of radula tracks in the wild 41.1Ch 41.1 Cepaea hortensis album. Radula track of unobserved species of gastropod on a pale butyl-rubber roof surface partly covered with algae. Magnified section on right. Oban, Scotland. September 2018. © C. Craik. (Craik & Anderson, 2018) show that the track of an unobserved gastropod species was linear with few radula strokes per head-swing on surfaces poor in alga not worth expending energy on, and changed immediately on reaching an alga-rich area to head swings five times wider with many more radula strokes per swing and a sinuous route, avoiding previously cleared tracks, to clear a non-linear patch of algae. In captivity on bare glass devoid of food, the radula of C. hortensis was not extended 29Ch 29 Cepaea hortensis heads. Pennine foothills, V.C. Derbyshire, England. August 2018. .
Activity is mainly nocturnal, avoiding dehydration and visual predators by spending daylight hours under stones or dense vegetation. They may be active in the open during daylight in humid weather without drying wind, sometimes with adverse results; on a humid morning two jackdaws cleared some garden steps of about 20 specimens in a few minutes, swallowing them whole. C. hortensis and C. nemoralis are the preferred molluscan food of thrushes (Boycott, 1934); piles of smashed shells are found around stones used as their “anvils” (image by G. Watson flic.kr/p/9yNrQD ) . Similar “middens” with many Cepaea shells are left by field mice and voles which bite open the spire, avoiding the reinforced aperture lip 42Ch 42 Cepaea hortensis. Shells of snails eaten by a rodent. At side of a large river in the Pennine foothills. March 1994. .
Water passes readily in and out of the highly permeable tissues and organs of molluscs so conservation and control of water are important for C. hortensis and other land molluscs. The principal source is osmotic absorption by the body and superficial mucus from wet and damp surroundings (Machin in Fretter and Peake, 1975), but water is also extracted efficiently from food so faeces are fairly dry 30Ch 30 Cepaea hortensis faeces. Pennine foothills, V.C. Derbyshire, England. September 2018. . Some water is lost with urine brought from the kidney by the ureter 21Ch 21 Cepaea hortensis mantle. Pennine foothills, V.C. Derbyshire, England. August 2018. to the mantle cavity close to the anus. Faeces and excreta leave the mantle cavity through the pneumostome. If the body surface becomes dry, water is transferred to it in exuded mucus. Much water is lost with foot mucus during locomotion 29Ch 29 Cepaea hortensis heads. Pennine foothills, V.C. Derbyshire, England. August 2018. & 43Ch 43 Cepaea hortensis starting to travel on glass. Pennine foothills, V.C. Derbyshire, England. August 2018. , so the snail reduces loss in dry conditions by retracting into the shell and ceasing movement. Activity also usually ceases in heavy rain when the body may become over hydrated or the mucus over diluted (Boycott, 1934; Machin in Fretter and Peake, 1975). In very dry weather, the snail retracts into the shelter of the non-permeable shell, seals the entrance with a transparent, elastic epiphragm made of a film of dried mucus 44Ch 44 Cepaea hortensis withdrawn with epiphragm. Pennine foothills, V.C. Derbyshire, England. August 2018. and may aestivate.
Locomotion is by monotaxic, direct, compression waves on the sole. On C. hortensis each wave is almost as wide as the sole, leaving only a narrow strip along each side that is not involved in the muscular waves. When travelling on glass, 3 or 4 transverse waves at a time may be discerned as slightly darker bands moving forwards on the sole 43Ch 43 Cepaea hortensis starting to travel on glass. Pennine foothills, V.C. Derbyshire, England. August 2018. . The bands are concave and raised slightly from the substrate. Though faint, their movement makes them more obvious when seen in action. Copious mucus is exuded by the foot to provide a film for it to move over.
Longevity: unlike most smaller species which have an annual life cycle, Cepaea hortensis can live longer; annual growth lines on adults often suggest a lifespan of about 3 years 7Ch 7 Cepaea hortensis. Pennine foothills, V.C. Derbyshire, England. August & September 2018. .

Distribution and status
Mainly North-West Europe: southern Scandinavia (Arctic Circle on coast of Norway) to Mediterranean coast of France and Mallorca, but scarce/absent on other Mediterranean coasts; east to Germany and Austria with a few records further east in Poland and Hungary, and a group of records in southern Finland, Estonia and Latvia. Probably scarce/absent in the Balkans. Introduced into North America; mainly Newfoundland to the Great Lakes and New York. GBIF map www.gbif.org/species/2294279 . Widespread and common in Britain up to Shetland, except for acid uplands in Scotland and Wales and historically, acidically polluted southern Lancashire; U.K. interactive map NBN records.nbnatlas.org/occurrences/search?q=lsid:NHMSYS0020…

Acknowledgements
I gratefully thank Clive Craik and Linda Pryke for use of their images, and Ben Rowson of the National Museum Wales for help in interpreting anatomical images, but any errors are my responsibility.

Links and references
Bargmann, H.E. 1930. The morphology of the central nervous system in the Gastropoda Pulmonata. J. Linn. Soc. (Zool.) 37 (250): 1 to 59.

Block, M.R. 1967. Dissecting Snails. Papers for students no. 8. London, the Conchological Society of Great Britain and Ireland.

Boycott, A.E. 1934. The habitats of land mollusca in Britain. J. Ecol. 22: 1 to 38.
Cameron, R. 2008. Land snails in the British Isles. Telford, Field Studies Council.

Cordero, A.M. (accessed October 2018) The phylogenetic distribution of darts in helicoid land snails. University of California, Berkeley.
www.ucmp.berkeley.edu/museum/75th/ab8.html

Craik, C. & Anderson, P. 2018. Fine art on a flat roof. Mollusc World 48: 26 – 27.

Fretter, V. & Peak, J. 1975. Pulmonates, functional anatomy and physiology. London, Academic Press.

Hudson, B. in Topley, P. 2006. Baker Hudson and some notes on Cepaea. Mollusc World 11: 8.

Janus, H. 1965. The young specialist looks at molluscs. London, Burke.

Jeffreys, J.G. 1862-69. British conchology. vol. 1 (1862). London, van Voorst. As Helix nemoralis var. hortensis Free pdf at archive.org/stream/britishconcholog01jeffr#page/184/searc… . Use slide at base of page to select pp.185 to 188.

Kerney, M. & Cameron, R. 1979. A field guide to the land snails of Britain and north-west Europe. London, William Collins.

Koene, J.M. and Schulenburg, H. (Mating) A love-dart at the heart of sexual conflict in snails. [Scanning Electron microscope of love dart of C. hortensis][CC BY 2.0 (creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
commons.wikimedia.org/wiki/File:Cepaea_hortensis_SEM_dart…

Lodi, M. & Koene, J.M. (2016) On the effect specificity of accessory gland products transferred by the love-dart of land snails. BMC Evolutionary Biology 16: 104. pdf at bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-016…

Pfleger, V. 1998. A field guide in colour to molluscs. Leicester, Blitz Editions.

Silverside, A.J. Lastdragon.org Biodiversity reference. Cepaea nemoralis (L.) Grove snail and Cepaea hortensis (O.F. Müll.) White-lipped snail. Accessed October 2018. bioref.lastdragon.org/Mollusca/Cepaea.html

Štamol, V. & Slapnik, R. 2015. Cepaea hortensis (O. F. Müller, 1774)
(Mollusca: Gastropoda) in Croatia? Nat. Croat. 24 (2): 331 to 336.
pdf at hrcak.srce.hr/file/220664

Zając, K.S. & Kramarz, P. 2017. Terrestrial gastropods – how do they reproduce? Invertebrate Survival Journal 14:199-209
pdf at www.researchgate.net/publication/317212919_Terrestrial_ga…

Current taxonomy: (WoRMS) www.marinespecies.org/aphia.php?p=taxdetails&id=1002172

Glossary
aestivate = to become dormant with a low metabolic rate, similar to hibernation, in response to warm, dry conditions.
alimentary system = organs for ingestion, digestion and absorption of food and the discharge of residual waste.
allosperm = sperm received from another individual. (Term used to avoid ambiguity of origin when discussing hermaphroditic reproduction.)
aperture = mouth of gastropod shell; outlet for head and foot.
atrium (genital) = cavity within genital pore leading to reproductive organs.
buccal mass = anterior of digestive system including an odontophore that supports anterior of radula, and a complex of muscles to operate them and other mouthparts.
bursa copulatrix = (a.k.a. spermatheca) copulatory pouch or sac for receiving allosperm for storage or partial consumption (sources differ on function; see caption of 36Ch 36 Cepaea hortensis. Dissection with reproductive organs isolated and spread out. Pennine foothills, V.C. Derbyshire, England. September 2018. ).
capillary vessels = fine branching blood vessels.
cartilages = (in gastropods) structures of tough, resilient material, histologically resembling vertebrate cartilage, embedded in tough connective tissue of left and right bolsters of the odontophore. Support and maintain shape of odontophore, and provide attachment for muscles controlling its movement.

cartilaginous = made of, or resembling, cartilage.
cerebral = to do with integration of sensory and neural functions to initiate and coordinate body activity.
chitin = semitransparent flexible horny protein.
chitinous = made of chitin.
columella = solid or hollow axial “little column” around which gastropod shell spirals; hidden inside shell, except on final whorl next to lower part of inner lip of aperture where hollow ones may end in an umbilicus or siphonal canal.

columellar = (adj.) of or near central axis of spiral gastropod.
columellar lip = lower (abapical) part of inner lip of aperture.
common duct = (a.k.a. ovotestis duct or little hermaphrodite duct) duct in hermaphrodite species from ovotestis to the albumen gland and/or prostate gland.
ditaxic = (of locomotion waves on foot) double series of waves, out of phase with each other, one series on each side of central furrow on sole.

direct = (of locomotion waves on foot) waves travel from posterior to anterior.
distal = away from centre of body or from point of attachment.
diverticulum(of bursal duct) = blind ended branch from the bursal duct for receiving allosperm for storage or partial consumption/processing (sources differ on function; see caption of 36Ch 36 Cepaea hortensis. Dissection with reproductive organs isolated and spread out. Pennine foothills, V.C. Derbyshire, England. September 2018. ).

epiphallus = extension of penis between the retractor muscle and junction of the vas deferens with the penis (strictly, an enlarged section of the vas deferens). Where body of spermatophore is formed.
everted = turned outside out and, like a sock, capable of turning outside in (inverted).
flagellum = long whiplike extension beyond the epihallus. Where the tail of the spermatophore is formed.
ganglia = knots on a nerve cord.
ganglion = a knot on a nerve cord.
haemocoel = system of interconnected spaces (sinuses) containing blood within body of a mollusc.

haemolymph = invertebrate blood.
height = (of gastropod shells) distance from apex of spire to base of aperture.
innervate = to arouse or stimulate a nerve or an organ to activity.
little hermaphrodite duct = (a.k.a. common duct or ovotestis duct) duct in hermaphrodite species from ovotestis to the albumen gland and/or prostate gland.

love dart = (a.k.a. gypsobelum) sharp, calcareous or chitinous dart which some hermaphroditic land snails and slugs stab each other during courtship. See 33Ch 33 Cepaea hortensis, love dart. Pennine foothills, V.C. Derbyshire, England. September 2018. and 36Ch (caption) 36 Cepaea hortensis. Dissection with reproductive organs isolated and spread out. Pennine foothills, V.C. Derbyshire, England. September 2018. .

mantle = sheet of tissue that secretes the shell and forms a cavity. In terrestrial gastropds (‘pulmonates’) the cavity roof contains a network of blood vessels enabling the cavity to act like a lung.

medial = midline of body or organ.
median = at/near centre of body as opposed to the sides.
monotaxic = (of locomotion waves on foot) single series of waves across complete width of foot.
ocular = of or connected with the eyes.

osmosis = movement of water or a solution through a selectively permeable membrane into a region of more concentrated solution, tending to equalize the concentration on either side of the membrane.

oviduct = internal duct to carry ova to the exterior.
ovotestis = hermaphrodite organ serving as both ovary and testis.
ovotestis duct = (a.k.a. common duct or little hermaphrodite duct) duct in hermaphrodite species from ovotestis to the albumen gland and/or prostate gland.

palatal lip = outer lip of gastropod aperture.
parietal lip ( or parietal wall) = inner side of gastropod aperture, often lacking clear lip structure with just a glaze on side of whorl adapically of columellar lip.

periostracum = thin horny layer of chitinous material often coating shells.
periphery = perimeter of the body whorl of a gastropod at its widest. Sometimes marked by a keel or coloured band.

odontophore = firm, usually medially grooved, approximately ellipsoid structure of cartilage supporting radula. Protruded like a tongue to operate radula. .

pneumostome = closeable breathing pore or respiratory opening in mantle of a pulmonate slug or snail.

prostate gland = gland that adds material to spermatozoa travelling through it to form semen.

proximal = towards the centre of the body or point of attachment.
proximate = very close to.
pulmonate = member of Pulmonata, one of three subclasses into which the class Gastropoda (slugs and snails) was divided during the 20th Century (other two were Prosobranchia and Opisthobranchia). This classification is no longer used by scientists, but pulmonate is a useful informal term to signify terrestrial slugs and snails, and freshwater snails, breathing atmospheric air through the lining of the mantle cavity, and with no operculum. There are also several freshwater and land prosobranchs. See en.wikipedia.org/wiki/Pulmonata

radula = ribbon of chitin bearing chitinous teeth that is extruded on a tongue-like odontophore of cartilage to rasp food.

spermatophore = a package made of mucoprotein containing an ejaculation of semen; created in the epiphallus and flagellum during copulation.

umbilicus = cavity up axis of some gastropods, open as a hole or chink on base of shell, often sealed over.
ureter = duct by which urine passes from the kidney out of the body.
vas deferens = tube carrying sperm to the penis.
vascular = relating to, containing or consisting of a vessel or vessels, especially those carrying blood.