CYRENA. 



21 



I have not been able to identify this species, which Mr. Hanley 

 informs me is very rare, the sliell labelled as such in the cabinet 

 of Mr. Cuming, he says is not the true C. jjlctceyis. 



" A beautiful and rare species, of which I have never seen but 

 my own specimen and that in the Jardiu des Plautes at Paris. 

 The sulci are close and regular, and the outline of the shell, 

 although not very unlike that of C. radiafa, is convex in front 

 of the beaks, thus rendering the front extremity broad and some- 

 what obtuse." — Hanley. 



I have reason to believe that this species i.s closely allied to 

 C. fontaineii. 



-Shell trigonal, solid, corn- 

 Fig. 16. 



16. Cyrena fontaineii, Carpenter 

 pressed, inequilateral ; ante- 

 rior side short, rounded ; pos- 

 terior narrow ; acute and an- 

 gular at extremity ; beaks 

 small, acute, eroded ; striae 

 fine, regular, epidermis smooth, 

 chestnut-brown ; interior of 

 the valves light-blue ; hinge- 

 margin curved, thick ; cardi- 

 nal teeth large, unequal, di- 

 vergent, the anterior ones bi- 

 fid ; lateral teeth unequal, an- 

 terior proximate, conical, pos- 

 terior distant, elongated, com- 

 pressed, a. fiintaimii. 



Long. 1.66; Lat. 1.40; Diam. 0.80 inches. 

 41; " 35; " 20 mill. 



Hah. South America. (Cabinets of Cuming, Jay and Prime.) 



Cy das fontaineii, D'Orb. Voy. Amer. 1844, 509, pi. 83, f. 14, 15. 

 Cyrena fontaineii, Carp. Mazatlan Shells, 1857, 114. 



Compared with C. olivacea, with which this species has been 

 confounded, its outline is more regular, it is smaller, more com- 

 pressed, the beaks are smaller and more acute, the epidermis is 

 smoother and of a different color. A rare species. 



l-y. Cyrena acuta, Prime.— Shell trigonal, oblique, transversely 

 elongated, very inequilateral, somewhat compressed, solid ; anterior side 

 short, rounded at end ; posterior side produced, angular at end ; beaks tu , 



