pSB:unoDON 1095 



Museum under the name MonocondyUea tninida of Morelet, 

 which is quite a different species, and Fischer and Crosse 

 gave it a new name. 



PSEUDODON CAMBODJENSIS (Petit). 



Shell subtriangular, subsolid, convex, inequilateral ; beaks 

 low, compressed ; posterior ridge full, rounded, ending bluntly 

 at the base of the shell ; anterior end narrowed, rounded ; dor- 

 sal outline curved, carried into a low wing behind ; dorsal slope 

 strongly and obliquely truncated; base line nearly straight; 

 surface with irregular, concentric growth lines, ashy-brown or 

 greenish-brown, subshining ; teeth single in each valve, large, 

 elevated, subtriangular; dorsal scars forming a row under the 

 beaks ; muscle scars irregular, impressed ; nacre flesh-colored, 

 somewhat silvery; ligamental patch large, dark, triangular. 

 Behind the teeth of old shells the epidermal matter covers the 

 hinge plate. 



Length 107, height 72, diam. 31 mm. 



Cambodia ; Tonkin. 

 Monocondylcca cambodjensis Petit, Jl. de Conch., XIII, 1865, 



p. 16, pi. IV, fig. 4. 

 Margaron f Monocondylcca) cambodjensis Lea, Syn., 1870, 



p. 72. 

 Pseudodon cambodjensis Simpson, Syn., 1900, p. 838. 



The National Museum possesses a fine series of shells of 

 this species, young and old. The young shells are rather 

 thin, but they become quite strong with age. The young shells 

 are more obovate and less distinctly triangular than those of 

 the adults. The peculiar fonn will distinguish this species. 



Pseudodon chaperi (de Morgan). 



Shell subrhomboid, somewhat inflated, solid, inequilateral ; 

 beaks only moderately full or high ; posterior ridge widely and 

 decidedly double, ending at the median line and near the base ; 

 anterior end narrowed and rounded ; base line lightly curved ; 

 dorsal line curved from the anterior end to the median line be- 

 hind, fullest just behind the ligament ; surface covered with 

 strong, concentric ridges ; epidermis thick, brownish. There 



