KEPORT ON THE GASTEROPODA. 431 



Natka clausa, G. 0. Sars, Moll. Arct. Norv., p. 159, No. 63, pi. xxi. figs. 12, 13, pi. v. bis, fig. 15, 



pi. xviii. bis, fig. 12. 

 „ affinis, G. O. Sars, Moll. Arct. Norv., p. 160, No. 64, pL xxi. fig. 14, pi. v. Us, fig. 16. 

 ,, clausa, Leclie, Novaja Sernlja &c. Hafs-Mollusker, K. Svensk. Vetensk.-Akad. Handl., vol. xvi., 



1878, pt. 2, p. 49, No. 93. 

 „ affinis, Monterosato, Enumerazione, p. 36. 



,, „ Norman, Moll, of Bergen Fjords, Journ. of conch., Jan. 1879, pp. 28, 74 (separate impres- 



sion), No. 200. 

 () ,, Darbishire (teste Gwyn Jeffreys' list of), Moel Tryfan Shells, Journ. Geol. Soc. Lond., 



1880, p. 354. 

 „ „ D'Urban, Zool. Barents Sea, Ann. and Mag. Nat. Hist., Oct. 18S0, ser. 5, vol. vi. 



p. 267. 

 „ „ Norman, President's Address Tyneside Nat. Club, 1SS1, p. 54. 



,, clausa, Dunker, Index Moll. Mar. Japon., p. 60. 

 „ affinis, Gwjn Jeffreys, "Triton" Moll., Proc. Zool. Soc. Lond., 1S83, p. 391 (Station 8, cold 



area, No. 5). 

 ,, ,, Gwyn Jeffreys, Bridlington Clay Shells, Journ. Geol. Soc. Lond., 1884, p. 319. 



,, clausa, Sowerby, Thes. Conch., pts. 39, 40, p. 96, sp. 125, pi. cccclvii. (iv. Gen.), fig. 48. 

 ,, ianthostoma, Sowerby, Thes. Conch., pts. 39, 40, p. 82, sp. 41, pi. cccclvii. (iv. Gen.), fig. 52. 

 ,, clausa, Verrill, MoLL New Eng., Trans. Connect. Acad., vol. vi. pt. 1, p. 26S. 

 „ affinis, Gwyn Jeffreys, Moll. "Lightning" and "Porcupine," Proc. Zool Soc. Lond., 1885, 



p. 35, sp. 16. 



Station 49. May 20, 1873. Lat. 43° 3' N., long. 63° 39' W. Off Halifax. 85 

 fathoms. Stones and gravel. Bottom temperature 35°. 



Habitat. — The North Atlantic from Greenland (Morch) to New England, 13 to 1255 

 fathoms (Verrill); and from the Mediterranean, 1415 fathoms (Monterosato 1 ), to Spitz- 

 bergen, 20 to 260 fathoms (Friele) ; Barents Sea, 25 to 160 fathoms (D'Urban); Nova 

 Zembla and at the Yenissei, 2 to 70 fathoms (Leche) ; Behring's Strait (Dall) ; Kamtskatka 

 (Deshayes) ; the Sea of Okotsk and the Schantar Islands (Middendorf) ; Japan (E. A. Smith 

 and Lischke). 



Fossil. — From the Pliocene (S. V. Wood), onwards from to 1360 feet (Gwyn 

 Jeffreys). 



Professor Sars (Joe. cit. supra) maintains the distinctness of Gmelin's species from that of Brode- 

 rip and Sowerby ; I have, however, followed the general opinion and united them, having utterly 

 failed to find trustworthy differences in the shells, and believing that the divergences which Professor 

 Sars has figured in the radula of the two forms are merely varietal, and are to be met with on even 

 a more extensive scale in almost every species. After very careful examination of the large series of 

 specimens of the British Museum I have, in spite of Dr Dunker, without hesitation followed Midden- 

 dorff and Schrenk in uniting Natica janthostoma, Desh., to Gmelin's species. The question is very 

 fully and discriminatingly discussed by Lischke (loc. cit. supra), who somewhat inclines to Midden- 

 dorff's view, but in the absence of a sufficient series of specimens allows Deshayes' species to stand. 



1 The Marquis of Monterosato (loc. cit. supra) states this on the authority of Gwyn Jeffreys, but I have 

 failed to find his reference. 



