1084 PSUUDODON 



show nuicli variation and approach pcguoisis very closely. 

 Some of them are much larger than Anthony's measurements, 

 as well as more inflated. The chief distinguishing character. 

 I take it, would be the full, high beaks of the latter, while those 

 of crchrisfriatiis are not so large or high. 



Section Pskudodon s. s. 

 Characters given under generic name. 



Group of Pscudodon Jmnnandi. 



Shell rather small, solid, rhomboid, short, intiated; posterior 

 ridge high, only slightly biangulate, faintly corrugated on the 

 posterior slope. 



PsKUDODON HARMANDi Crosse and Fischer. 



Shell long rhomboid, inflated, solid, inequilateral ; beaks ap- 

 parently somewhat elevated but not inflated; anterior end 

 rounded ; base nearly straight ; dorsal and post-dorsal outlines 

 curved, being almost subangular behind the ligament ; poste- 

 rior ridge somewhat double, ending in a biangulation at and 

 above the base of the shell ; surface for the most part smooth, 

 having some irregular growth lines on the disk and a few, 

 subradial corrugations on the dorsal slope; epidermis dark 

 brown or blackish, shining ; in each valve there is a subcom- 

 pressed smooth tooth ; muscle scars well impressed ; dorsal 

 scars few, deep, arranged in a row under the beaks ; nacre 

 lurid purplish. 



Length 62, height 40, diam. 29 mm. 



Cambodia. 

 Pseudodoii Iianiiaiidi Crossd and Fischer. Jl. de Conch., 



XXIV, 1876. p. 331. pi. X, fig. 2.— Simpson. Svn., 1900, p. 



836. 

 Monocondylcca harmandi Va\T%j., Conch. Sam.. Ill, 1890, p. 



174. 



A solid, rhomboid, much inflated species with shining, al- 

 most black epidermis. The posterior ridge is rather high, and 

 behind it the dorsal slope falls away abrujitlv. 



