Tritia nitida (left) height 26.3 mm and T. reticulata (right) height 27.2 mm from Blackwater Estuary, Essex, England, September 2019. Leg. S. Taylor.

Odd numbers T. nitida. Even numbers T. reticulata.

1: convex whorls.

2: almost flat whorls (except convex on columellar side of body whorl).

3: translucent parietal lip exposes colour of underlying body whorl.

4: opaque white parietal lip, semicircular, conceals colour of body whorl.

5: protoconch eroded on this one and all T. nitida in sample.

6: protoconch intact.

7: siphonal canal meets palatal lip at obtuse angle (120° in this case).

8: siphonal canal meets palatal lip at acute or right angle (80° in this case).