3-50 PLIOCENE MOLLUSCA. 



Although T. truncatus is found at present in British seas, its range is principally 

 northern and arctic, extending from Spitsbergen and Barents sea to Greenland 

 and thence to Canada and the New England coast. T. clathratus, which occurs 

 with it as a fossil at Wexford, though not so abundantly as the former, is 

 a Scandinavian and circumpolar species. 



Var. major (Br/argger). Plate XXXVI, fig. 25. 



1848. Fusvs Banffius, Reeve, Conch. Icon., vol. iv (Fusus), pi. xxi, fig. 90 (in text), fig. 91 (on plate). 

 1872. Trophon scalariformis, juv., S. V. Wood, Mon. Crag Moll., 1st Suppl., p. 26, pi. iii, fig. 10; 



T. Bamffius, p. 26, pi. iii, fig. 11. 

 1901. Trophon truncatus, var. major, Br0gger, Norges geol. Unders^gelse, no. 31, p. 654, pi. v, fig. 11. 



Varietal Characters. — Larger than the type but with similar sculpture, varying 

 somewhat in size and form, having a short canal and sometimes an expanded 

 mouth. 



Dimensions. — L. 15 — 20 mm. B. 8 — 12 mm. 



Distribution. — Recent .• British and northern. 



Fossil : Waltonian Crag : Little Oakley, probably elsewhere in 

 Red Crag. Wexford, March, Bridlington, Clyde beds. Christiania fiord. 



Remarks. — The Wexford specimen figured under this name corresponds with 

 Prof. Bro'gger's var. major from the Pleistocene of Christiania, and with those 

 given by Wood from the Clyde beds and from March (ojj. cit., figs. 10, 11). It is 

 an enlarged form of T. truncatus, characteristic of northern seas, occurring also in 

 our Pleistocene beds and very common at Wexford. M. Dautzenberg considers 

 one of the specimens of Murex Bamffius, figured by Donovan, as equivalent to 

 M. clathratus, Linne. 



Var. intermedia, nov. Plate XXXVI, fig. 24. 



Varietal Characters. — Larger than the type, and longer and more slender in the 

 spire than the variety major. The longitudinal costaa are fine and numerous as in 

 T. truncatus. 



Dimensions. — L. 15 mm. B. 6 mm. 



Distribution. — Fossil .- Wexford. 



Trophon (Boreotrophon) clathratus (Linne). Plate XII, fig. 25; Plate XXXVI, 



figs. 3—6. 



1870. Trophon clathratus, S. V. Wood, Jr., Quart. Journ. Geol. Soc, vol. xxvi, p. 92. 

 1880. Trophon clathratus, Stewart, Proc. Belfast Nat. Field Club, Appendix, p. 175. 

 1898. Trophon clathratus, Posself, Med. om Gr0nl., p. 176. 



