TROPHON (BOREOTROPHON) CLATHRATUS. 351 



1901. Trophon clathratus, var. major, Br^gger, Norges geol. Unders^gelse, no. 31, pp. 497, 562, pi. vi, 



fig. l!». 

 1910. Trophon clathratus, 0yen, Krist. Vid. Selsk. Forh., no. 5, p. 27. 

 1910-15. Trophon clathratus, Odlmer, Archiv Zool., K. Svensk. Vet.-Akad., vol. vii, no. 4, pp. 13, 24, 



1910; var. grandis, K. Svensk. Vet.-Akad. Handl., vol. liv, p. 176. 



1914. Trophon clathratus, F. W. Harmer, Plioe. Moll. Gt. Brit., pt. i, p. 127, pi. xii, fig. 25. 



1915. Trophon clathratus, A. Bell, Geol. Mag. [6], vol. ii, p. 168. 



1915. Trophon clathratus, Johnson, Bost. Soc. Nat. Hist., Occ. Papers, vol. vii; Fauna of New 

 England, pt. xiii, p. 131. 



Distribution. — Fossil: Wexford, Boulder-clay of Belfast (additional). Pleisto- 

 cene : Reykjavik (Pjeturss). 



Remarks. — The type form of this ventricose and northern shell, generally 

 known as Trophon cloth rat us, is clearly distinct from those described above as 

 T. truncatiis or its varieties. I have specimens of the former in my collection from 

 the Waltonian Crag of Oakley, from Bridlington, Uddevalla, the Pleistocene of 

 Christiania and elsewhere ; they are practically the same, showing no indication 

 of any close relationship to the latter species. Wood adopted Gould's name of 

 scalariformis for the Crag form, including under it a variety (a) which corresponds 

 with Prof. Sars' figure of T. clathratus : and another (f3), a more slender shell, with 

 finer sculpture and a longer canal ; for this I now propose the varietal name 

 attenuata (figs. 7 and 8). The latter variety agrees with the Fusus lameltosus of 

 Gray 1 in its fine sculpture and long canal, but the body- whorl of Gray's shell is 

 ventricose and the spire is very short, besides which his name had been used by 

 Borson in 1821 for a different species. The dwarf form (fig. 6) I call var. minor. 



Mr. C. W. Johnson identifies the Fusus scalariformis of Gould with the present 

 shell (op. cit.), while M. Dautzenberg employs that specific name for a variety of 

 T clathratus. 2 The latter authority adopts, however, T. clathratus and T. truncatus 

 for the two species now in question, in which I follow him. 



As pointed out by Wood (' Mon. Crag Moll./ pt. i, p. 48) the Fusus scalariformis 

 of Nyst is a different species. 1 



The Crag Murex peruvianas of Sowerby (' Min. Conch.,' vol. v, p. 47, pi. 

 ccccxxxiv, fig. 1) may perhaps be the same ; Lamarck's Fusus Feruvlanus is 

 different. 



Var. attenuata, nov. Plate XXXVI, figs. 7, 8. 



1848. Trophon scalarlforme, var. /3, S. V. Wood, Mon. Crag Moll., pt. i, p. 48, pi. vi, fig. 7c. 



Varietal Characters. — More slender and somewhat smaller than the typical 



1 Zool. Beechey's Voyage, p. 118, pi. xxxvi, fig. 13, 1839. 



2 Camp. Scient, Pr. Monaco, vol. xxxvii (Mollusques), p. 150, 1912. 



40 



