IIl6 PAKRUYSIA 



Fea are before me, is much like it, but is a little brighter col- 

 ored. One ot them has considerable zigzag sculpture scattered 

 over the disk. 



Burma ; India. 

 Unio tvienibobis Benson, Jl. As. Soc. Beng., XXXV, 1855, p. 



144. — Han LEY and Theobald, Conch. Ind., 1876, p. 43, pi. 



cvii, fig. 2. 

 Parre\sia tor'oyensis var. trieiiibolns Simpson, Syn., tqoo, p, 



844". 

 Unio houngdaraniciis Tai'peronk-Canefki. Ann. Mus. Civ., 

 VI[, 1889, p. 341. 



Parki'YSia vulcanus (Hanley). 



Shell subtriangular, solid, inequilateral, green throughout 

 except the anterior extremity ; strongly plicate or tuberculately 

 corrugated ; anterior end somewhat narrowed, rounded ; pos- 

 terior end wider, rounded below, subtruncated obliquely above ; 

 base line lightly arcuate ; beaks high ; hinge strong ; pseudo- 

 cardinals solid, lacerated ; anterior muscle scars deep ; nacre 

 white, slightly iridescent. 



Length ^^, height 25 mm. 



Burma; Pegu. 

 Unio vulcanus Hanley, Pr. Zool. Soc. Lond., 1875, p. 606. — 



Hanley and Theobald, Conch. Ind., 1876, p. 62, pi. clv, 



H- 3- 

 Parreysia vulcana Simpson, Syn., 1900, p. 844. 



A very distinct species apparently, having a moderately near 

 relationship to P. mandelayensis. It is, however, not so trian- 

 gular as that species, being somewhat obovate, and its sculp- 

 ture is more decidedly tuberculate. It is more nearly equilat- 

 eral than that species. 



Parreysia fe.t; fTapperone-Canefri). 



Shell subtriangular or subrhomboid, rather inflated, sub- 

 solid or solid, somewhat inequilateral ; beaks high and full, 

 with irregular zigzag-radial sculpture : posterior ridge well 

 developed, narrowly rounded, curved, sometimes partly double, 

 ending in a blunt point or biangulation below the median line ; 



