•xA^^ 



JOURNAL 



OF THE 



ASIATIC SOCIETY 



Part II.— PHYSICAL SCIENCE. 



No, IV.— 1873. 



Desceiptions of New Species of IJNiONiDiE. — By W. Theobald, Esq 

 [Received July 29th, 1873 ; read August 6th, 1873.] 

 (With plate XVII.) 

 Unio bhamoets^sis, n. s., PL XVII, Fig. 1. 



Testa subtriangulato-ovatd, postice acuminata, margine ventrali modice 

 rotundato, umbonihus tumidiusculis, IcBvigatis, pustulis parvis aliquando 

 armatis, decoy^ticatis. JEpidermide tenuissimd, loevi, subpolitd, Icete viridi, 

 in senioribus flavescente. Testa conceyitrice subrugatd, lineis paucis sive 

 rugis angustis ligamentum versus plus minusve subradiatim notatd, et antice 

 ruqis paucis perhrevibus leviter corrugatd. Dentibus cardinalibus lamellatis, 

 et denticulatis, in valrd dextrd smgulo, onuUifisso, in sinistra gemino, poster i- 

 ore triangulari et umbonem juxta posito, anteriore lamelliformi, striata. 

 Nacred argented et iridescente. 



Hab. prope Bhamo, regno Birmanico ; necnon in Prome occidentali 

 Brovincid Begu. 



Lat. 52, alt. 40, crass. 26 mm. 



A rare species in Western Prome where alone I have met with it in 

 Pegu, and renvarkable for its smooth thin epidermis. The posterior slope 

 alone is conspicuously ornamented with sculpture, but in my largest speci- 

 men from Bhamo and in some others also, the peculiar sculpturing of XT. 

 hurmanus, W. Blfd. is faintly but distinctly perceptible over part of the 

 valves towards the umbones especially. A small specimen of 3G mm. from 

 Western Prome exhibits distinctly also the two rows of spines wliich cha- 

 racterise the next species, so that it seems that IT, burmanus, U. bhamoensis 

 27 



