52 FAUNA OF BALUCHISTAN. 



3. OEDER : DESMODONTA. 

 1. Family: PHOIABOMYIDM. 

 Genus: PHOLADOMYA, Sow. 



Pholadomya indica, spec. nov. PI. XIII. fig. 7-7a. 



The shell is apparently of moderate size only, the length of the specimen being 

 44 mm. and its height about 32 mm,, transversely oval in shape and very inequi- 

 lateral. The beaks, which are quite close to the anterior margin, are low, depressed, 

 and slightly tumid ; the valves are moderately inflated on the anterior part, but 

 slightly compressed in the posterior direction. The ornamentation consists of about 

 23 fine radiating ribs, which begin quite close to the anterior margin and extend 

 over niearly the whole surface of the shell. The ribs are all of equal strength, but by 

 the numerous strong concentric striae of growth they appear to be divided into 

 radiating lines of somewhat irregular low granules. 



Locality and stratigraphical position. — Dds valley, horizon 8. 



Memarks. — The only species which bears any likeness to the s,pecimen described 

 above, is the tertiary Pholadomya puschif Goldf., if any comparison can be made 

 with a specimen so badly preserved, where one of the chief distinctive features 

 is the general outline of the valves, 



Pholadomya Tigris, spec. nov. PI. XIII. fig. 6-6a. 



Besides the species just described, there is another cast belonging to this genus, 

 which belongs to a decidedly different species. The shell has apparently attained a 

 considerable length, as, although damaged at the anterior side, it still measures about 

 93 mm. in length, the height being 56 mm. Its general shape was apparently 

 rectangular, the ventral margin being nearly parallel to the hinge margin, but very 

 inequilateral. The anterior side is very short and apparently cut off straight ; the 

 posterior side is elongated but not expanded. Although the anterior margin is not 

 visible, it seems that it was nearly straight and joined the straight ventral margin at 

 an angle of about 90° ; hinge margin straight, posterior margin rounded. The 

 beaks are low, depressed, and close to the anterior margin. Valves highly inflated, 

 but somewhat compressed towards the posterior side. Ornamentation consisting of 

 18 to 20 coarse radiating ribs which spread over nearly the whole surface, beginning 

 quite close to the anterior margin, leaving only a small area free towards the 

 posterior and hinge margin. 



Locality and stratigraphical position. — D^s valley, horizon 2. 



Memarks.— l:]m species exhibits a great likeness to Pholadomya elliptica^ 

 Miinst,, as regards the transversely elongated shape of the valves, but it differs 

 apparently by a much shorter anterior side, and the probably straight anteriq? 



