Ib4 unio'Id.t:. 



double in the rirjld ; lateral teeth long, thin, bladed and nearly 

 straight ; anterior cicatrices distinct; posterior cicatrices confluent ; 

 dorsal cicatrices situated nearly in the centre of the cavity of the 

 beaks ; cavity of the beaks exceedingly shallow ; nacre pearly 



white and iridescent It closely resembles the U. margi- 



nalis of Lamarck, but differs from that species in being more 

 transverse, in the beaks being more refuse, in the dorsal line 

 being nearly straight, and in its not being possessed of a light 

 border along the margin. The cardinal teeth are remarkably thin, 

 and form nearly a line with the lateral teeth." 



Subsp. generosus (Gould). 



Unto f/enerosus. Gould, Proo. Boston Soc. Nat. Hist, ii, 1847, 

 p. 220; Otia Conch. 1862, p. 210; H. & T.. C. I. 1876, p. 22, 

 pi. 46, f]g. 4 ; Pastel, Conch. Sam. iii, 1890, p. 153. 



Margaron {Unio) f/enerosus. Lea, Syn. 1870, p. 29. 



? Unio lanielldtus, Sowerby, Conch. Icon, xvi, 1868, pi. 94, llg. 511. 



Lcnnellidens genero$iis (Gould), Simpson, Washiugton, D.C, Smiths. 

 Inst., Nat. Mus. Proc. xxii, 1900, p. 857. 



Onginal clescrij)twn : — Testa magna, solida, transversa, oblougo- 

 ovata, inequilaterali, antice rotundata et angustata ; postice ob- 

 liquata, suhrostrata, ad apicem triuicata ; margine ventrali arcuata, 

 dorsali recta, abscendente ; umbonibus contiguis hand elevatis ; 

 valvis subtumidis radiatim substi'iatis, postice subcostatis, epider- 

 mide fuliginosa, disco nitido : dentibiis remotis ; cardinalibus 

 elongatis, obliquis, laminatis : margarita alba vel salmonacea 

 limbo iridescente. 



Long. 64, lat. 95-5, diam. 38-25 mm. 



Hab. Newville, Tavoy (J//'s. Vinton); specimens in the Indian 

 Museum are labelled respectively Myadong, L^pper Burma 

 (Anderson), Maudalay (AnnandaJe), and Bhamo (J. Coggin 

 Brown). 



Subsp. jenkinsianns (Benson). 



Unio jenkinsianus, Benson, A. M. N. II. x, 1862, p. 185 ; H. & T., 

 C.I. 1876, p. 19, pi. 41. fig. 4; Pfetel, Conch. Sam. iii, 1890, 

 p. 155. 



Lamellidens jenkinsianus (Benson), Simpson, Washington, D.C, 

 Smiths. Iiist., Nat. Mus. Proc. xxii, 1900, p. 857. 



Original description : — Testa transverse elongata, subacuminato- 

 ovata, valde ina?quiiatera]i, tumida, crassa, antice brevi rotundata, 

 postice elongata, mini me alata, superne sensim descendente, 

 demum angusta, obtusa ; margine basali antice convexiusculo, 

 postice subrecto ; ligamento brevi ; disco vakle tumido, transverse 

 plicato ; epidermide picea, versus marginem ventralem olivacea ; 

 umbonibus leviter couvexis, decorficatis,apicibus obtusis ; denfibus 

 arcuatim sit is, crassiusculis, erosis, cardinalibus elongatiusculis, 



