TROCHUS. 299 



Var. 3. Icevior. Smaller, more conical, solid and glossy, 

 quite smooth with the exception of one or two slight spiral 

 ribs on the uppermost whorls, fleshcolour. 



Habitat : At the roots of Laminarice and on stones, 

 from low-water mark to 40 f., in the west of Scotland, 

 the Orkneys, and Shetland ; local but not uncommon. 

 The Rev. Mr. Whyte, according to Dr. Gordon, found 

 it in Dunnet bay, Caithness, and Mr. Hyndman has 

 dredged dead specimens in Belfast Bay ; but the latter 

 are suspiciously like fossils from a submarine post- 

 tertiary deposit in that locality. Var. 1 is occasionally 

 met with. Var. 2 was taken by Mr. Barlee at Skye, 

 and by myself at Loch Carron. For the other variety 

 I am also indebted to the same friend. T. Groenlandi- 

 cus occurs in the Clyde beds (Smith and others), Fort 

 William (J. G. J.), Norwich Crag (Woodward), and 

 at Uddevalla. It lives in every part of the Arctic 

 Ocean, and on the coasts of the White Sea, Scandi- 

 navia, Iceland, Canada, and the States of Maine and 

 Massachusetts. 



Its habits are much the same as those of the last 

 species. Their shells may be distinguished by this 

 having a more conical form and greater solidity, by the 

 spiral ribs and striae on the upper surface, the deeper 

 suture, and also by the deeper and angulated umbilicus. 

 The size of some specimens considerably exceeds the 

 average dimensions which I have given. The largest 

 I have seen were obtained by Dr. Otto Torell in Iceland. 

 The fry are white, and striated like the adult. 



It is perhaps the Turbo fuscus of Miiller^s ^ Prodro- 

 mus^ [" testa fulva striis elevatis transversis^^), and Tro- 

 chus cinerarius of Fabricius but not of Linne. The 

 Rev. R. T. Lowe described it as Turbo carneus, G. B. 



