Undulating spiral ribbon of spawn. Specimen on right has typical large, soft, conical tubercles. One on left has them contracted/less well developed, and they resemble the tubercles on some other species. Other features need to be considered for identification such as the voluminous gills with the opaque white star just visible edge-on. The accomplished Alder & Hancock based a separate species, Doris subquadrata 1845, on a single specimen with small conical tubercles (see fig. 04.2) so it is not surprising that those with small tubercles still often cause confusion. Scotland, August 2015. © J. Anderson.