24 



ing a sinuosity at the posterior inferior angle. Hinge of two deeply 

 cleft divergent teeth in the right valve, (or four arranged in pairs,) 

 and three in the left, of which the middle one is unequally bifid. 

 No lateral teeth. Siphonal sinus acute, extending to the centre of 

 the valve. 



Length one and three fifths inches ; height one and a half inches ; 

 breadth seven eighths of an inch. 



Inhabits Mazatlan. Lieut. Green. 



This shell has very nearly the outline of Cyth. prostrata, espe- 

 cially its pouched ventral margin, but is much more ventricose and 

 very different in sculpture. It is also very much like A. tennis, 

 Sowb., but is larger, and has a distinct lunule. A. Chinensis is also 

 allied in form. 



TELLINA MINI AT A (Plate XVI. Fig. 1.) 

 Tettina miniata, Gould; Proc. B. S. N. H., Nov. 1851, IV. 90. 



T. transversa, ovata, tenuis, valde hians, convexiuscula, concentrice striata, 

 erubescens; apicibus antemedianis ; latere autico semiovali; latere postico 

 ovato-triangulari ; margine ventral! subpendulo ; intus miniata ; cardo dentibus 

 binis divaricantibus tenuibus utraque valvft instructus ; nymphis conspicuis. 



Shell transversely ovate, thin, widely gaping posteriorly, slightly 

 convex, delicately striate concentrically, with vestiges of numerous 

 radiating strise ; deep roseate at the beaks and across the middle of 

 disks, and zoned with roseate elsewhere : beaks anterior, acute ; 

 anterior end semioval ; posterior end ovate-triangular, acute at tip, 

 which is near the median height ; dorsal margin slightly declin- 

 ing; ventral margin a little depending at middle. Interior bright 

 rose-red throughout : siphonal sinus opposite the middle of the ven- 

 tral margin, pyramidal and truncated at tip. Hinge with two deli- 

 cate, diverging, equal cardinal teeth in each valve ; nympha? strongly 

 developed. 



Diam. longitudinal two inches ; vertical one and one fourth 

 inches ; transverse five eighths of an inch. 



Inhabits San Juan. Lieut. Green. 



Compared with the analogous West India species, T. rosea, Gmel., 

 it is longer, thinner, less lenticular, more inequilateral, more acu- 

 minated posteriorly, ventral and posterior margin less convexly 

 arcuate ; color more roseate externally, and altogether so internally. 



