94 



the genus Paxillus, described by my brother and myself in the 

 ' Annals ' a few months ago. We there considered the genus to be- 

 long, possibly to Auriculidce ; but an examination of this species, 

 and a better knowledge of the locality where the shells have been 

 found, lead us to place them amongst the Helicidce. 



DiPLOMMATiNA Bensoni, A. Adams. D. testa minima vix ri- 

 mata sinistrorsa, cylindrico-ovata, costellata, costidis distan- 

 tibus obliquis regularibus ; anfractibus sex, convexis, apice 

 subobtuso ; apertura rotundata ; peristomate duplicato, ex- 

 terna expanso rejlexo, interna recta, margine fiexuasa. 

 Hab. On the banks of a river, Moreton Bay, E. Australia {Mr. 

 Strange) . 



This very pretty little shell agrees in all its characters with the 

 genus Biplommatina of Mr. Benson, after whom I have named it. 

 There is some difficulty in the location of this genus. Mr. Benson 

 says distinctly that the eyes are " on the posterior part of the teiita- 

 cula, at their base," but he says there is no operculum. Mr. Gray, 

 on the other hand, has described the operculum. The true position 

 is probably in Truncatellidce. 



Crassatella speciosa, a. Adams. C. testa transverse ovata 

 suhcequilaterali, pallida, epidermide tetiut fusca induta, can- 

 centrice plicata ; plicis confertis regidaribus; latere pastico 

 rotundato, antica acuminata subrostrata, angulata, margine 

 ventrali canvexa, antice sinuato. 

 Hab. Bay of Campeachy. Mus. Cuming. 



The beaks in this species are acute and close together, and rather 

 more deeply plicate than the rest of the surface of the valves ; there 

 is an obtuse oblique and angular ridge extending from the urabones 

 to the ventral margin. 



Crassatella l^evis, A. Adams. C. testa ovato-transversa 

 crassa, tumida, subcequilaterali, castanea, Icevigata, cancentrice 

 striata, natibus subsulcatis ; latere postico rotundata, antica 

 producta subrostrata, margine oblique truneata, carina obtusa a 

 natibns ad basin decurrente instructo, posteriori sulcata, mar- 

 gine ventrali canvexa antice sinuato. 

 Hab. La Guayra {M. Le Marie, French Navy). Mus. Cuming. 

 A large smooth pale chestnut shell beaked anteriorly and with a 

 prominent obtuse keel extending from the beaks to the fore part of 

 the ventral margin, and a broad shallow groove behind it ; the lunule 

 is ovate lanceolate, and the beaks are transversely sulcate. 



Crassatella obscura, A. Adams. C. testa avato-trigonali, 

 transversa, subcequilaterali, compressa, nigra-fusca, apicibus 

 transverse carrugata, ad umbanem plicata ; latere antica 

 rotundato, postico subtruncato ; margine valvarum intus cre- 

 nulato. 



Hab. China Seas, deep water. Mus. Cuming. 



A small brown-black species, with the valves only plicate near the 

 beaks and their inner margins finely crenulated. 



