138 Mr. E. A. Smith on Arctic MoUusca. 



much larger than the ordinary size of the species that it almost 

 appears that it must be distinct. It measures 21 millims. in 

 length, being about double that of Gould's figure. Hancock 

 mentions one from the west coast of Davis Strait, which was 

 about five eighths of an inch (or 16 millims.) long. 



Natica affinis, Gmelin, 



Syst. Nat. p. 3675 ; Morcli, Moll. Gronl. 1857, no. 56. 



Natica clausa, Broderip and Sowerby, Zool. Journal, vol. iv. p. 373 ; 



Beechey's Voyage, pi. .34. f. 3 ; Reeve, Conch. Icon. ix. f. 113 ; Gould, 



Invertebrata Mass. f. 167, (ed. 2) f. 612. 

 N. consolidata, Couthouy, Bust. Journ. Nat. Hist. vol. ii. 1839, p. 89 ; 



Philippi, Conchylien, pi. 1. f. 11. 

 JV. septentrinnaUs, Beck, Miiller, Naturbist. Tidsskr. 1842, p. 80. 

 N. borealis (Beck), Gould, /. c. p. 238, (ed. 2) p. 343. 

 Y&v. =N.Janthosto7na,'Deshii,jes, Mag. de Zool. 1841, pi. 45j Reeve, 



Conch. Icon. ix. f. 79 a, h. 



Hah. Dobbin Bay, 30 fms., bottom stones and mud (//. G. 

 Hart, Aug. 1876). 



Only a single small specimen was obtained, which is re- 

 markable for having the spire rather more elevated than 

 usual. 



There is another species figured by Philippi, on plate i. figs. 

 2 and 3, under the name affinis, which is totally distinct from 

 the present one. 



In the description of this species Gould expressly remarks 

 that it is " marked by stri» of growth onlyj'"' and that the 

 epidermis is " thin, bony." I presume that the last word 

 should be horny ; for there is nothing bony in the nature of the 

 epidermis. As regards the sculpture, I find that all specimens 

 I have examined distinctly show spiral striatlon, which, how- 

 ever, is very minute, and can only be seen by the aid of a 

 lens. The animal is briefly described by Jeffreys in the ' An- 

 nals & Mag. Nat. Hist.' April 1877, p. 318. The variety 

 {N. janthostoma) is usually rather more globular than normal 

 specimens ; and the umbilicus is frequently scarcely filled up 

 by the callosity, as in arctic examples. N. occlusa, Searles 

 Wood, a fossil from the Red Crag, an allied species, yet pro- 

 bably is distinct on account of its much more produced spire. 



Trochus {Margarita) umbilicalis, Broderip and Sowerby, 



Zoological Journal, 1829, iv. p. 371. 



? Trochus gronlandicus, Chemnitz, Conch. Cab. v. pp.12 & 108, f. 1671. 



Hah. Franklin-Pierce Bay, 15 fms. ; Mushroom Shore, 

 82° 29' N. 



This species is also reported by Jeffreys, ' Annals & Mag. 

 Nat. Hist. 1877, March, p. 237, from " Discovery Bay, and 



