PLATE CXXVIL 



writer, *' must own I have never met with this species since on any 

 other British coasts." We have since seen it among parcels of shells 

 from the Mediterranean, and also find that it has been discovered by 

 the late Dr. Pultney, on the North sliorc, Poole ; and at \\ eymouth. 



The specific character of the Gmelinian Trochus Granafum, 

 seems to accord very nearly with our shell *, but it is about twice the 

 size, and inhabits the Southern Ocean ; and it is certainly more pro- 

 bable, as some conchologists have suggested, that it is the variehj of 

 Trochus Zizyphinus, described by Linnseus in the Mils. Iiegif2^t 

 as being ** tota pallida, anfractihus basl gibbis, striatis, subtitissime 

 punctis papilloris," It differs from Zi/.vphinus in having the anfrac- 

 tus a little rounded, and the wreaths being enc irdcJ with granulated 

 spiral ridges. The name Da Costa has already given it, is very ap- 

 plicable; and as it has undoubtedly escaped the notice of Gmelin, 

 there can be no impropriety in retaining it. — It is evidently one of the 

 rarest British species of the Trochus genus. 



* Testa pyramldali alba coccineo vaiia basi .suliconvexa ; spira? anfiactibas convexis; 

 •ingulis granorum moniformibus, primis duybus jrijxin-.is. Gr/nf. 5i>H4. <^. 108. 



