Il68 LAMKl.lJDENS 



elliptical, though sometimes slightly rhomboid as described by 

 Lamarck, the younger shells are smooth and polished, while 

 older ones are often somewhat rough. 



Var. obesus (Hanley and Theobald). 



A giant form, which does not exhibit any banding and is 

 much swollen. The surface is dark brown or blackish. 



Length 127, height 69, diam. 45 mm. 

 Unio marginalis var. obesa Hanley and Theobald, Conch. 



Ind., 1876, p. 20, pi. XLiii, fig. 3. 

 Lamellidcns marginalis var. obesus Simpson, Syn., 1900, p. 



855. 

 fUnio corrianus Sowerby, Conch. Icon., XVL 1868, pi. lxxvii, 

 fig. 401. 



Var. tricolor (Kuster). 



Shell fulvous with a broad outer yellowish band, the dorsal 

 slope greenish with darker rays. 

 Unio tricolor Kuster, Conch. Cab. Unio, 1856, p. 156, pi. xlv, 



fig. I. 

 Unio marginalis var. tricolor HanlEy and Theobald, Conch. 



Ind., 1876, p. 20, pi. XLii, fig. 5. 

 Lamellidens marginalis var. tricolor Simpson, Syn., 1900, 



p. 855. 



It is doubtful whether this is worthy of a varietal name. 



Var. candaharicns (Hanley and Theobald). 



Shell rhomboid, the dorsal and ventral outlines nearly 

 straight and parallel ; ashy brown, green on the dorsal slope. 

 Unio marginalis var. candaharica Hanley and Theobald, 



Conch. Ind., 1870, p. 20, pi. xliii, fig. 4. 

 Lamellidens marginalis var. candaharicus Simpson, Syn., 1900. 



p. 855. 

 Var. cylindricus (Hanley and Theobald). 



Very much elongated, dorsal and ventral outlines nearly 

 straight and parallel ; posterior end pointed about on the median 

 line ; color brownish. 



Length 108, height 48, diam. 30 mm. 



