134 PLIOCENE MOLLUSCA. 



Distribution. — Not known living-. 



Fossil : Waltonian Crao- : Little Oaklev. Newbouiniian. But- 

 leyan. Scaldisien : Belgium. 



Bemarks. — Li the fourth volume of the British Conchology, p. 317, Jeffreys, 

 describing the Recent T. muricatns, expressed the opinion that the fossil shell 

 known to Nyst under that name was a different species. It seems probable that 

 he was referring to that afterwards figured by the latter author {op. cit.) which 

 departs materially from it both in form and texture, being shorter and more solid. 



I was at first inclined to adopt Jeffreys' view, but as the shell in question 

 undoubtedly belongs to the muricatns group, which appears to have been a 

 variable one in Crag times as it now is in the Mediterranean, I think it better to 

 regard it as a variety of that species. 



I have found a number of specimens corresponding with Nyst's figure at 

 Oakley and in other parts of the Crag; the one now represented comes from Butley. 



Trophon Lamplughi, sp. nov. Plate XII, fig. 22. 



1903. Trophon muricatns, Lamplugli, Mem. Geol. Surv., Isle of Mau, p. 475. 



Specific Characters. — Shell small, turreted, solid ; whorls convex, slightly 

 angulate above, with a sloping shelf below the suture, the last more than half the total 

 length ; ornamented by narrow, clearly marked and prominent longitudinal costae, 

 15 on the last whorl, extending to the base of the shell, continuous across the 

 sutural shelf and occasionally varicose, as well as by spiral ridges which cross the 

 cost£e and are closely crowded together on the shelf; spire ending in a blunt point, 

 the topmost whorls smooth ; suture deep ; mouth oval ; outer lip slightly angulated 

 by the keel, not thickened or denticulated within as in T. muricatns; canal narrow, 

 inclining slightly to the left. 



Dimensions. — L. 13 mm. B. 6 mm. 



Distriljution. — Not known living. 

 Fossil : Isle of Man. 



RemarJis. — The Manx fossil figured under this name was found hj the Rev. 

 S. N. Harrison and is now in the Jermyn Street Museum, where it bears the name 

 of T. muricatiis. It seems to be full grown and, except that the apex is wanting, 

 is perfect and unworn. In sculpture it differs so materially from any variety of 

 that shell known to me that I am disposed to regard it as specifically distinct. Its 

 outer lip, moreover, wants the internal denticulation characteristic of the former. 

 As I am unable to discover anything else to which it can be satisfactorily 

 referred, I dedicate it to my friend Mr. Lamplugh of H.]\I. Geological Survey, 

 the author of the Memoir on the Isle of Man. 



