io88 psr.unoDON 



Monocondykca collingen P.TiTeu, Conch. Sam., Ill, 1890, p. 



174. 



There is no reference to any plate or figures in the descrip- 

 tion of this species given by Mousson, but the three figures 

 on plate XVIII, are probably intended to represent it. Num- 

 ber I is probably some other species, while 2 represents an 

 elongated rhomboid shell with a double posterior ridge, which 

 is quite strongly developed, and ends in a wide, decided bian- 

 gulation behind. I have before me an author's specimen of 

 Alasmodonta zollingeri, from the Morelet collection, which 

 exactly agrees with Mousson's figure 2 on the plate XVIII of 

 the ''Mollusken von Java." 



PsEUDODON IN0SCU1.ARIS (Gould). 



Shell irregularly rhomboid, rather solid, slightly inflated, 

 the greatest inflation being just behind the middle of the shell, 

 inequilateral ; beaks not prominent ; posterior ridge high, dou- 

 ble, ending in a wide, distinct biangulation at' and below the 

 median line ; anterior end somewhat narrowed, rounded ; base 

 line almost evenly curved ; post-dorsal outline high and almost 

 angled behind the ligament, subtruncate behind; surface with 

 irregular growth lines and sometimes with a few, faint, subrad- 

 ial plications on the dorsal slope ; epidermis tawny-brown, 

 subshining ; teeth single in each valve, blunt and rounded ; 

 dorsal scars few, forming a row under the beaks, deep; muscle 

 scars shallow ; nacre lurid brownish. 



Length 74, height 48, diam. 25 mm. 



River vSalwen, British Burma. 

 Anodon inoscularis Gould, Pr. Bost. Soc. N. H., I, 1844, p. 



160. — Hanley and Theobai,d, Conch. Ind., 1876, p. 5, pi. 



IX, fig. 2. 

 Margaron (Afonocondylcea) inoscularis Lka, Syn., 1870, p. y;^. 

 Margarifana inoscularis Fmtpj., Conch. Sam.. III. 1890, p. 173. 

 Pseudodon inoscularis Simpson. Syn., iQOo, p. 837. 



Close to P. cumingii, but shorter, solider and a little fuller. 

 I have before me a single specimen and a valve belonging to 

 the Lea collection bearing the name An. inoscularis, from the 

 author of the species. It is considerably more solid and in- 

 flated than P. 7'ondembuschianits. 



