﻿238 DESCRIPTIONS OF 



posterior cicatrices confluent, very large and very slightly impressed; dorsal cicatrices 

 small, placed in the centre of the cavity of the beaks; cavity of the shell rather deep 

 and wide; cavity of the beaks very shallow and rounded; nacre either purple or 

 white and iridescent. 



Remarks. — This is very closely allied to An. crepera herein described, and may, 

 perhaps, when more specimens of the old and young of both species are compared, 

 prove only to be a variety. The specimens before me, however, differ in the tenuis 

 being rather thinner and less elliptical, the outline inclining to obovate. The exist- 

 ence of teeth in the young, and the rudiments on the dorsal line in the adult, are 

 very similar to the crepera. Of the four specimens before me, two have the nacre 

 purple and two white. The beaks are too much eroded to observe any marks of 

 undulations, except in one case. 



Anodonta crepera. PI. 34, fig. 117. 



Testa laevi, elliptica, subinflata, valde insequilaterali ; valvulis temiibus, antice crassioribus ; natibus sub- 

 prominentibus ; epidermide fusco-virente, obsolete radiata ; margarita vel alba vel purpurea et valde 

 iridescente. 



Shell smooth, elliptical, somewhat inflated, very inequilateral ; valves thin, thicker 

 before ; beaks somewhat prominent ; epidermis greenish brown, obsoletely radiated ; 

 nacre white or purple and very iridescent. 



Anodonta crepera, Lea. Proc. Zool. Soc, Lond., 1850, p. 198. 



Hub. — Bongabon, Luzon, Philippines. H. Cuming. 



My cabinet and cabinet of Mr. Cuming. 

 Diam. 1*1, Length 1*8, Breadth 3'3 inches. 



Shell smooth, elliptical, somewhat inflated, very inequilateral, rounded behind ; 

 substance of the shell thin, thicker before and diaphanous behind ; beaks somewhat 

 prominent; ligament rather short, rather thin and light brown; epidermis greenish 

 brown, obscurely rayed, striate, shining towards the beaks, with distant lines of 

 growth ; umbonial slope slightly raised and very slightly rounded ; posterior slope 

 raised into a carina, striate and dark brown ; anterior cicatrices distinct, slightly 

 impressed ; posterior cicatrices confluent, large and very slightly impressed ; dorsal 

 cicatrices placed in the centre of the cavity of the beaks ; cavity of the shell rather 

 deep and wide ; cavity of the beaks very shallow and very much rounded ; nacre 

 white or purple and very iridescent. 



Remarks. — Five of the six specimens under examination are purple, the sixth 

 whitish. The outline is nearly oval. One of the specimens is obtusely biangular 

 posteriorly ; the substance of the shell is slightly thickened anteriorly; the beaks are 

 too much eroded to observe any undulations. This species is closely allied to' A. 

 tenuis, but is not quite so thin, and is more transverse. Three specimens of the 



