302 Records of the Indian Muse:tin. L VOL. Van} 
74. Parreysia annandalei, sp. n. 
Shell oval, convex, moderately solid, coarsely concentrically 
ribbed, covered with a thin, smooth, brownish-olivaceous perios- 
tracum; umbones rather small, not prominent; dorsal margin 
arched; ventral margin considerably rounded; anterior side 
slightly produced and rather sharply rounded; posterior side very 
bluntly sub-rostrate; cardinal teeth two in each valve, somewhat 
anteriorly situate, rather coarse, corrugated; lateral teeth strong, 
curved; anterior scars rather small, very deeply excavated ; 
posterior scars also small, ovate, deeply impressed; interior of 
shell whitish, iridescent. 
Long. 29, lat. 41, diam. 20 mm. 
Hab.—Gowhatty, Reg. No. 2490 [Typei. 
75. Parreysia perconvexa, sp. n. 
Shell ovate, slightly curved, very convex, solid, but much 
eroded, where intact covered with a dark blackish brown perios- 
tracum ; umbones moderately large; dorsal margin sloping in an 
anterior direction; ventral margin slightly curved posteriorly; 
anterior side gently rounded; posterior side slightly and very 
bluntly produced, rounded ; cardinal teeth very anteriorly situate 
with upper surface multi-ridged and supported in each valve by an 
enormous column-like callus thickening of the shell; lateral teeth 
coarse, rather short, curved; anterior muscular scars of great 
depth; posterior scars subcircular, well impressed; interior of shell 
very pale greenish white. 
Long. 37, lat. 55, diam. 33 mm. 
Hab.—Nangyong Lake, Reg. No. 5°89 [Type]. 
Gen. Lamellidens, Simpson, 1900. 
Subgen. Lamellidens, Simpson, Igoo. 
76. Lamellidens marginalis (Lamarck), Simpson, Syn. 
Naiades, Proc. U.S. Nat. Mus., XXII, p. 854,—Unio marginals, 
Lamarck, An. sans Vert., VI, 1819, p. 79; Deshayes, Enc. Méth., 
II, 1827, p. 151, pl. ccexlvii, fig. 1= Die breite Mahler-Muschel 
aus Gronland, Schroter, Flusse.,1779, p. 181, pl.ix, fig. 1? Unio 
ervoenlandicus, Mérch, Am. Jl. Conch., IV, 1868, p. 38,=— ? Unio 
testudinarius, Spengler, Skriv. Selsk. Nat., III, 1793, p. 65,—= 
?Unio truncatus, Spengler, Skriv. Selsk. Nat., III, 1793, p. 65= 
Margarita (Unio) marginaiis, Lea, Syn., 1836, p 37; 1838, p. 24, 
—Margaron (Unio) marginalis, Lea, Syn., 1852, p. 38; 1870, 
p. 60,=Unio anodontina, Lamarck, An. sans Vert., VI, 1819, 
p. 80,=Unio anodontinus, Kuster, Conch, Cab. Unio., 1861, p. 240, 
pl. ixxx, fig. 15,—Symphynota bilineata, Yea, Tr. Am. Phil. 
Soc, TV, 1831, p. 98) pl. xi; stig 1p Ose rr834ap: ese pl 
xi, fig. 19,—Margarita (Unio) bilineatus, Lea, Syn., 1836, p. 38; 
1838, p. 25,=Umio bilineatus, Hanley, Test. Moll., 1842, p. 207 ; 
Biv. Shells, 1843, p. 207, pl. xxi, fig. 30.=Margaron (Unio) 
bilineatus, Lea, Syn., 1852, p. 38; 1870, p. 61,= ?Unio evanescens, 
Mousson, Moll. Java., 1849, p. 91, pl. xvii, fig. 2. 
