448 THE VOYAGE OF H.M.S. CHALLENGER. 



Natica pusilla, De Kay, Nat. Inst. New York, p. 123, pi. vii. fig. 145. 



„ livida, Bean in Thorpe's Brit. Mar. Conch., p. 265. 



„ gouldii, Philippi, 1845, Zeitschr. f. Malak., p. 77. 



,, grmnlandica, Seailes Wood, Crag Moll., Pal. Soc, vol. i. p. 146, sp. 10, pi. xii. fig. 5. 



„ grijnlandica, Lov6n, Index Moll. Scand., p. 17. 



„ pusilla, Philippi, Conch. Cab. (ed. Kiister), p. 88, No. 100, pi. xiii. fig. 5 (not pi. xv. figs. 10, 11). 



„ greenlandica, Reeve, Conch. Icon., vol. ix. pi. xxi. fig. 96. 



„ pusilla, Forbes and Hanley, Brit. Moll., vol. iii. p. 341, pi. c. fig. 7. 



,, groenhtndka, J. G. Jeffreys, Brit. Conch., vol. iv. p. 216, voL v. pi. lxxviii. fig. 2. 

 Lunatia grmnlandica, G. O. Sars, Moll. Arct. Norv., p. 158, pi. xxi. fig. 15. 



Natica gramlandica, Sowerby, Thes. Conch., pts. 39, 40, p. 96, sp. 129, pi. cccclxii. (ix. Gen.), fig. 140. 

 Lunatia pallida, Dunker, Ind. Moll. Mar. Japon., p. 61. 



Natica pallida, Gwyn Jeffreys, Moll. "Lightning" and " Porcupine," Proc. ZooL Soc. Lond., 1885, 

 p. 29, sp. 2. 



Station 151. February 7, 1874. Lat. 52° 59' 30" S., long. 73° 33' 30" E. Heard 

 Island, S.S.E. of Kerguelen. 75 fathoms. Volcanic mud. 



Habitat. — Greenland (Moller), and Norway (Eeeve), and United States north coast, 

 also the Cattegat (Philippi) ; Great Britain, south to the Dogger Bank, Ostend ; 2 to 

 1290 fathoms (Jeffreys). 



Fossil. — From the older glacial clays of Norway (Sars) ; and of Scotland, Sweden, 

 Iceland, and North America (Jeffreys) ; the English Crag (Wood). to 400 feet. 



On comparing this Natica with G. O. Sars' specimens from Norway I am not quite satisfied, and 

 yet I cannot part them. The Kerguelen specimen has a smoother, more ivory-like surface, is stronger, 

 the spire is more depressed and has a more truly conical outline ; the apex is more sunken, the 

 whorls are flatter, the body-whorl below the suture is slightly hollowed, the pad on the inner lip is 

 larger, and the umbilicus is more completely closed than it is in any specimen of the Arctic species 

 I have seen ; but Natica gronlandica varies in all these respects, and the study of that species leaves 

 the impression that the differences I have mentioned above might be found filled up. Still, it was 

 unsatisfactory to put a Kerguelen shell to an Arctic species without fuller conviction, and I was glad, 

 therefore, to have my determination of the species confirmed by Mr E. A. Smith. The thin horny 

 operculum, too, has precisely the microscopical short curved scratch-like lines which are a well-known 

 feature in Natica gronlandica. 



Dr Gwyn Jeffreys (loc. cit. supra) identifies Natica gronlandica, Beck, with the Natica pallida of 

 Brod. and Sow. (Zool. Journ., vol. iv., 1828, 1829, p. 372), but I cannot follow him here. It is 

 quite possible that the Natica pallida of Gray (Beechey's Voyage "Blossom," pi. xxxiv. fig. 15, without 

 description), of Middendorff (Malac. Boss., vol. ii. p. 93), and of Philippi (Conch. Cab., ed. Kiister, 

 p. 96, sp. 100, pi. siv. fig. 2), may be Natica gronlandica, Beck, though all three authors assert the 

 contrary ; but of the correctness of Gray's identification of the " Blossom " species as that of 

 Broderip we have no evidence, Broderip's type having disappeared, and the original description having 

 no figure, and being so absolutely featureless that it might apply to anything. Dr Gwyn Jeffreys 

 himself says that he had been " inclined to doubt whether it might not be Natica islandica." The 

 state of the case is this. Some shells called Natica pallida, Brod. and Sow., are Natica gronlandica, 

 but whether they really are Broderip and Sowerby's species no one can tell. 



