Top-shells and Fheasant-sliell 203 



The animal is covered with short prickl}' points, and 

 the tentacles— which are marked with t]>ree lines 

 of brown— have blunt tips. The eyes are on the 

 under-side of tubercles at the outer base of each 

 tentacle. Side appendages tln^ee pairs, with a brown 

 eye-spot just behind each. It occurs chiefly in the 

 west of Scotland, but has been taken on many other 

 parts of our coasts, even to Devon, Cornwall, and the 

 Channel Islands, in from 2 to 70 fathoms. 



The Grooved Top-shell (T. striatus) is narrow at 

 base in proportion to height, flattened beneath, the 

 whorls 7 in number, of which the lowest 5 

 are flattened and distinctly keeled. The whole 

 surface is crossed by innumerable oblique lines 

 which break up some of the ridges into little knobs. 

 The oTOund colour is whitish, streaked obliquely or 

 speckled with brown. It is about a third of an 

 inch across at base, and a little more in height. 

 It occurs along the south coast from Dorset to 

 Cornwall, in the Channel Islands, and at Cork, 

 Baltimore, Bantry, and Dublin Bay; its habitat 

 from low water to a depth of 15 fathoms, and it 

 appears to be fond of the Grass Wrack (zostera). 

 Montagu's Top-shell {T. montacuti) is similar to 

 T. striatu.% but a little smaller, the whorls not 

 flattened— though somewhat compressed— and the 

 base more convex. It occurs on all our shores 

 between 7 and 95 fathoms. 



In all the foregoing species of Top-shells there 

 is no umbilicus in the adult, though the fry of 

 some species show one temporarily. All the species 

 that follow have this perforation, tliough in the 

 Thick Top it is almost filled up in the adult. 



