130 PLIOCENE MOLLUSCA. 



Althoucrli T. trimcatus is allied to T. clatliratus, a common fossil of the Pleisto- 

 cene deposits, the equivalent, as just stated, of T. scalariformis of Gould and Wood, 

 it has been generally regarded as distinct. Jeffreys l)elieved it to be so at first, 

 but in 1877 {op. cit.) adopted the view that it was a variety of T. datliratus. 



The shell figured by Forbes and Hanley under the latter name (Brit. Moll., 

 vol. iv, pi. cxi, fig. 1) appears to be T. Bamffifis. 



T. clatlirafus and T. truncatus are northern species ; both are recorded from 

 Norway, Iceland, Glreenland, Barents Sea, and the eastern and western coasts of 

 North America, but only the latter ranges southwards toAvards Great Britain.^ 



I have found T. trancatiis in the Butleyan Crag at Bawdsey ; Gwyn Jeffreys 

 gives it from Uddevalla, and Prof. Br0gger from the Yoldia-c\ay of Christiania. 



In their recent work. MM. Dautzenberg and Fischer regard T. cJathratvs and 

 T. truncatus as distinct. 



Trophon Fabricii (Beck), Moller.' Plate XII, figs. 27, 28. 



1780. Tritonium craticulatnm, Fabricius, Faun. Groenl., j). 400. 



1842. Trophon Fabricii (Beck), Moller, lud. Moll. Grceul., p. 14. 



1845. Murex borealis, Reeve, Couch. Icon., vol. iii (Murex), pi. xxx, fig. 145. 



1872. Trophon craticulatus, S. V. Wood, Mon. Crag Moll., 1st Suppl., p. 25, tab. iii, fig. 1. 



1877. Trophon Fahricii, Jeffreys, Ann. Mag. Nat. Hist. [4], vol. xix, p. 325. 



1878. Trophon craticulatus, Gr. O. Sars, Moll. Reg. Arct. Norv., p. 248. 



1887. Trophon craticulatus, Kobelt, Icon, schaleutrag. europ. Meereseonch., vol. i, p. 27, pi. vi, figs. 



11, 12. 

 1899. Trop)hon Fahricii, Posselt, Medd. om Gronl., vol. xxiii, p. 174. 

 1903. Trophon (Fusus) Fabricii, Lamplugh, Mem. Geol. Survey, Isle of Man, p. 475. 



Sijecific Characters. — Shell fusiform; whorls 6, rapidly diminishing in size, the 

 last two-thirds the total length, the upper part angulated, with a sloping shelf 

 below the suture ; ornamented by about 10 longitudinal prominent and sometimes 

 varix-like ribs of unequal size, and by raised spiral lines, equal to the spaces 

 between them ; spire elongate, scalariform ; suture deep and well-marked ; mouth 

 oval, outer lip hardly angulated by the keel, not denticulated within ; canal short, 

 open, turning slightly to the left. 



Dimensions. — L. 35 mm. B. 22 mm. 



Distribution. — Recent : Spitzbergen, Finmark, Iceland, Greenland, Labrador, 

 Gulf of St. Lawrence, Wellington Channel, Behring Sea. 



^ The difference between the two shells is well shown in the specimens figured by Prof. G. 0. Sars 

 (pi. XV, figs. 9, 10). 



" The specimen figured under the above name in the Survey Memoir of the Isle of Man, p. 336, 

 fig. 87, as from Cranstal Point, is in reality the one found by Captain James in the Wexford gravels, 

 described below as var. Bailyi. That variety does not occur in the Manx beds, although a specimen 

 of the typical form has been found there, as stated below. 



