Mr. R. B. Hinds's Descrij)tlo7is of new Shells. 257 



sinens ; columella valde arcuata, superne callosa ; labium exter- 

 num acutum ; umbilicus parvus. Epidermis lajvis. 

 C. serotinus. 



Geog. Port Anna Maria, Nuliuhiva, Marquesas. 

 Shell somewhat fusiform, the last two whorls turbinate, 

 whence a spire, less than half the length of the body-whorl, 

 suddenly ascends; everywhere smooth, except the spire, which 

 is nodulose and transversely ridged, and covered with the re- 

 mains of a brown epidermis. The last whorl much lengthened, 

 squarish, flattened, and not at all ventricose ; the apei'ture 

 terminating in a short effuse canal, and towards the centre 

 expanded, from the conformation of the columella. Outer lip 

 thin and sharp ; inner not at all produced. Columella with 

 a large callosity above, arcuate in the centre, corresponding 

 to a contraction which occupies the circumference of the last 

 whorl. A smaller callosity below assists to cover the umbi- 

 licus. Axis 39 lines. 



I am disposed to place this new genus among the Pyru- 

 lid(B, in which group it holds an analogous situation to Swain- 

 son's genus of fossil shells, Clavalithes, among the Turbinel- 

 lidce. The structure of the spire, formation of the canal, and 

 peculiar convolution of the lower whorls seem to display its 

 affinities here. But as the plaits on the columella are variable 

 in Clavalithes, and Cyrtulus may still be confounded with it, 

 the points of difference will be found in the short expanded 

 canal, deeply incurved columella, and in the absence of the 

 papillary spire, — a character on which Mr. Swainson dwells, 

 as being indispensable to the existence of his genus. 



1, Plios Veracjuensis. Testa ovata, elongata, costulata ; costulis nu- 

 merosis sequalibus, lineis elevatis decussatis et cancellatis ; anfrac- 

 tibus subplanulatis, superne fuscis, inferne albidis ; ultimo albo 

 fasciato. Axis 15 lin. 



Geog. Pueblo Nueva, coast of Veragua ; dredged in some num- 

 bers from 26 fathoms, mud. 



This may be regarded as the American analogue of the 

 Asiatic shell, Phos senticosus. 



2. P. crassus. Testa ovata, elongata, solida, costata ; costis rudlbus 

 subdistantibup, lineis impressis decussatis ; labio externo grandi- 

 dentato, interne prorsum producto. 



Geog. Panama and Gulf of Fonseca ; dredged as solitary shells in 

 from 3 to 14 fathoms, mud. 



The characters of this shell are all prominent. It is solid, 

 the ribs large and coarse, crossed by prominent lines ; teeth 

 on the outer lip large, internal ridges strongly marked ; inner 

 lip considerably produced forwards. The colour is a lightish 

 brown, somewhat deeper on the ribs. 



Ann. ^ Mag. N. Hist. Vol. xi. S 



