1: Five thin grooves on columellar neck of siphonal canal on T. reticulata.

(worn away on some specimens.)

2: Three grooves on columellar neck of siphonal canal on T. nitida.

3: Light sienna flesh with dark blotches on T. reticulata.

4: Whitish grey flesh with dark blotches on T. nitida. The siphon is so heavily pigmented on some T. nitida as to appear black (Rolan & Luque, 1994, state it as the norm in Table 1). See fig. 63.

Left:  T. reticulata, Dorset, England, April 2012. Right:  T. nitida, Oosterschelde, Netherlands, June 2017, © S. Verheyen.