﻿PILSURYOCONCHA 243 



dulate sculpture, situated at 1-5 (in the young 1-4) of the 

 length; nacre bluish, towards the beaks lurid yellow. 



a) Long. 118, alt. vert. 53, alse 69, diam. 2^ mm. 



b) Long. 103, alt. vert. 45, alae 55, diam 22.5 mm. 



c) Long. 88, alt. vert. 35, alae 47, diam. 18 mm. 



d) Long. 68, alt. vert. 2^, alae -^J, diam. 12 mm." (von 

 Martens). 



Type locality. Lake Danau-Baru, Indragiri, Sumatra. 

 Anodonta cxpressa von Martens, Nachr. Deutsch. Mai. Ges., 



1900, p. J2. 



"Nearest to A. exilis Lea from Siam and A. polita Mouss. 

 from Java, but it is easily distinguished in the mature form by 

 the greater height of the posterior half of the shell. The four 

 specimens before me form an age series and show that the 

 proportion of height to length increases noticeablv with age ; 

 the two younger shells, c and d, remind one verv much of A. 

 polita from Java, especially as in c the bright yellow border is 

 also present, but the ventral margin is a little more convex 

 posteriorly and the posterior margin descends more direct 

 from the wing. In the older shells, a and b, this is still more so. 

 In the young shells the surface is somewhat dull, but is polish- 

 ed in the older ones, which are of a dark brown color like the 

 two species referred to." 



PiLSERYOCONCHA C-ARINIFERA (Conrad). 



Shell narrow, elliptical, compressed, thin and fragile ; an- 

 terior side narrow, rounded at the extremity ; posterior side 

 produced, subcimif orm, truncated at the extremity ; hinge mar- 

 gin long, straight, elevated, slightly ascending from the ante- 

 rior to the posterior extremity ; beaks not elevated above the 

 dorsal line; basal margin straight in the middle; color of epi- 

 dermis oliA^e-green inferiorly, darker aibove; hinge margin 

 without a callus. 



Length 65, height 30, diameter not given. 



Southeastern Asia, probably. 

 Anodonta carinifera Conrad^ Cover of Monographv, No. 9, 



Pilsbryconcha carinifera Simpson, Syn., 1900, p. 588. 



