PELECYPODA. g 



species by the peculiar sculpture of the lunula and the escutcheon 

 but it has a very near relative in the living Nucula mitralis, Hinds. 



ASTARTE (P) DUBIA, Spec, nov., Plate I, Fig. 8— 8a. 



Shell sub-triangular, rather flat, and •moderately inequilateral. 

 The beaks are short but pointed, situated forward of the median 

 line ; anterior side short, posterior side somewhat expanded. Surface 

 covered with fine regular horizontal ribs, which are separated by 

 furrows of equal breadth. Lunula large, but ill-defined, and only 

 limited by a thin line ; hinge not known, ventral margin apparently 

 smooth. 



Locality. — Rather rare at Yenangyat. 



Remarks. — It is with some doubt that I include this form among 

 the genus Astarte> as the hinge is not known, but so far as can be 

 judged from the external features, it certainly belongs to the family 

 of Astartidse ; it is quite probable that this form may be found else- 

 where in Burma, and then further details may be given. So far as 

 can be judged, the species is of medium size, as all the specimens 

 under examination do not exceed 15 mm. in height and length. 



BATISSA CRAWFURDI, Spec, nov., Plate II, Fig. 1-4; Plate III, 



Fig. 1 — ic. 



The shell is cordiform, triangular, thick and inequilateral ; beaks 

 in the anterior third of the length. The anterior margin is round 

 and shortj and passes gradually into the ventral margin which is 

 nearly straight ; the posterior margin is slightly curved and forms 

 nearly a right angle with the former ; dorsal margin short and curved. 

 Beaks thick, slightly curved inwards, frequently deeply eroded. 

 Ligament strong; hinge strongly developed ; there are three cardinal 

 teeth in each valve, the anterior one being the shortest and slightly 

 inclined backwards ; the two following are inclined forwards, the 

 posterior one being elongated, but thinner than the others. A large 

 compressed anterior and posterior lateral tooth in the left valve, both 

 very finely striated, and fitting into corresponding sockets in the 

 right valve. Surface smooth except some strongly marked striae 



( 9 ) 



