I 174 LAMia.LlOKNS 



Unio scutum Sowerbv, Conch. Icon., XVI, 1868, pi. xciv, fig. 



510. — Hanley and Theobald, Conch. Ind., 1876, p. 22, pi. 



XLVI, fig. I. 

 Lamellidciis scutum Simpson, Syn., 1900, p. 857. 

 l.amellidcns marginalis var. scutum Prkston, Rec. Ind. Mus., 



VII, 1912, p. 304. 



A much elongated rhomboid species, the dorsal and basal 

 outlines being nearly straight and parallel. According to 

 Sowerby the epidermis is pitch color. 



Var. humilior (von Martens). 



"Somewhat lower, but on the whole agreeing well with the 

 typical form ; young shells of a lively brownish-green, older 

 ones blackish. Basal margin nearly straight in young shells, 

 slightly incurved in mature ones. Posterior ridge well marked 

 near the umbones. Teeth tubercular, but proportionally small. 



Length 124, height at beaks 49, at postero-dorsal angle 56, 

 diam. 26 mm. Beaks situated at 2/9 of the length, postero- 

 dorsal angle at 2/3 of the length.'' (von Martens). 



Type locality, Chindwin River near Kalewa, Upper Burmah 

 and its tributary, the Yu River. 

 Unio scutum var. Iiuiuilior von AIartens, Arch, fijr Naturg., 



I. 1899, p. 45, pi. v, fig. I. 



"The younger specimens of this form have a great likeness 

 in their outer appearance to U. marginalis var. anodontinus of 

 the Conch. Ind., pi. 42, fig. 7, but they should have thinner 

 teeth to belong to marginalis." 



Lamellidens corrianus (Lea)." 



Shell irregularly long elliptical, thin, convex, inequilateral; 

 beaks low ; posterior ridge but slightly elevated, rounded, end- 

 ing in a blunt point about on the median line ; dorsal outline 

 straight or nearly so ; dorsal slope obliquely truncated ; anterior 

 end a little narrowed, rounded, slightly cut away below ; sur- 

 face nearly smooth ; ei>idermis ashy-olive, with radial rows of 

 very delicate wrinkles on the anterior end, brilHantly polished 



