236 Dr. J. Gwyn Jeffreys on 



fms. Labrador (Dawson, fide Packard). St. John's Har- 

 bour, Newfoundland (Verkrlizen). Fossil in Norway, Swe- 

 den, Scotland, and the east of Ireland. 



The genus Molleria differs from Turbo in the same way 

 that Cyclostrema does from Trochus^ i. e. in having a complete 

 peristome. In Molleria and Turbo the operculum is cal- 

 careous, in Cyclostrema and Trochus it is chitinous. 



Trochus cinereus, Couthouy. 



Turbo cinereus, Coutli. iu Boston Journ. Nat. Hist. vol. ii. p. 99, pi. 3. 

 f. 9. 



Body yellowish-white : head semicircular and hood-like, 

 notched at the outer edge ; it is furnished with a small trian- 

 gular lappet or flap on each side : tentacles cylindrical and 

 thread-shaped, finely ciliated : eyes small, black, placed on 

 short bulbs at the outer base of the tentacles : foot thick, 

 * squarish in front and bluntly pointed behind ; it has 6 cirri 

 or filaments on each side, which are ciliated like the tentacles, 

 and are of different sizes and lengths. 



Waigat Strait, 15-25 fms. ; Station 4, 20 fms. ; 5, 57 fms. 

 West Greenland (Moller and others). East Greenland 

 (Mobius). Spitzbergen, 5-15 fms. (Torell, Kroyer). Iceland 

 (Steenstrup and others). Norway, 10-130 fms. (Sars and 

 others). 'Lightning' Expedition, 170 fms. (dead). 'Por- 

 cupine' Expedition, 1869, 173 fms. (dead). Eastern coasts 

 of North America, from Mackenzie River southwards to Cape 

 Cod, 7-150 fms'. Mexico (British Museum). Fossil in 

 Norway and Sweden, Shetland, Scotland, Ireland, and Ber- 

 wick Bay. 



A Spitzbergen specimen of the variety Groenlandica, Mol- 

 ler, measures | of an inch in breadth. Specimens vary in the 

 height of the spire as well as in the character of the sculpture. 

 The outer layer in one of my Greenland specimens having 

 been mostly removed by erosion, the surface of the inner 

 layer presents a pearly appearance. 



Fabricius appears to have considered this species a variety 

 of his T. cinerarius (not Linne's species of that name), which 

 is the T. Groinlandicus of Chemnitz. Broderip and Sowerby's 

 specific name striata (1829) has precedence of Couthouy 's 

 (1839) by ten years ; but we have already a Linnean species 

 of the same name. It is possibly the Margarita arctica of 

 Leach ; although his description in the Appendix to Sir 

 John Ross's voyage (1819) is too vague for determination, 

 and may apply to T. Grcenlandicus ; it is " -M. purpurascente 

 carnea — tenuiter striolata, operculo testaceo." 



