LAMELLIDENS. 185 



valva3 sinistraD subsimplicibus, dextrae duplicibus laminatis, laterali- 

 bus remotis subelongatis, valvse sinistrse duplicibus, lamina interna 

 demum incrassata ; margarita violaceo-albida, iridescente. 



Long. 52, lat. 94, diam. 38 mm. 



Hdb. Brahmapootra River, Assam. The following localities 

 are, among others, attached to specimens in the Indian Museum : 

 Sylhet, Bhagalpur (Captain Shenvill). 



Subsp. sawaddyensis, Preston, Eec. Ind. Mus., Calcutta, vh', 

 1912, p. 305. 



Original description : Shell much more ovate and convex than 

 the typical form, having the dorsal margin more arched and 

 posteriorly ascending, the ventral margin and anterior side more 

 rounded, and the posterior side produced and roundly rostrate. 



Hub. Sawaddy River. Specimens in the Indian Museum are 

 labelled Bhamo (Dr. J. Anderson) Shuaygoomyo, Upper Burma 

 (Dr. J. Anderson), and Mandalay (Dr. N. Annandale). 



The type is in the Indian Museum. 



311. Lamellidens pulcher (Tapparone-Canefri). 



Lamellidens pulcher (Tapparone-Canefri) ; Simpson, Washington, 

 D.C., Smiths. Inst., Nat. Mus. Proc. xxii, 1900, p. 856. 



Unio pulcher, Tapparone-Canefri, Ann. Mus. Civ. St. Nat. Geneva, 

 vii, 1889, p. 350. 



Original description: Testa tenui, subcompressa, ina3quilaterali, 

 transverse ovata, subquadrata, postice dilatata, sub-biangulata, 

 area postica depressa, margine ventrali rectiusculo, umbonibus 

 haud eminentibus, rarius integris, sa3pius breviter decorticatis. 

 Superficies valvarum Ia3vis, nitida, rugis concentricis minutis, 

 subregularibus, sa3pe obsoletis exarata; pallide olivaceo-castanea, 

 radiis duobus ina3qualibus in area postica fuscis vel viridibus 

 picta. Dentes cardinales parvi, laminati, infero in valva dextera 

 crassiusculo, subtruncato, superne acuto. Margarita argentea, 

 superne luteo-carnea vel luteola. 



Long. 43, lat. 70, diam. 22 mm. 



Bab. Meetan, River Houngdaran (L. Fea). 



The author also describes two varieties of this species as 

 follows : 



Var. lamellatiformis. 



Testa magis postice dilatata, inferne bisinuata. 

 Long. 43, lat. 76, diam. 21 mm. 



Var. ponderosus. 



Testa majore, crassiuscula, magis lata, subquadrato-oblonga, 

 superficies valvarum castanea vel castaneo-fusca. 

 Long. 48, lat. 84, diam. 28 mm. 

 Both the varieties are from the same locality as the type. 



