graf II. B. PrestON: The -Aszatic Natades. 295 
Gen. Pseudodon, Gould, 1844. 
Sec. TRIGONODON, Conrad, 1865. 
52. Pseudodon (Trigonodon) crebristriatus (Anthony), 
Simpson, Syn. Naiades, Proc. U.S. Nat. Mus, XXII, p. 835,—= 
Monocondylaea crebristriata, Anthony, Am. Jl. Conch., I, 1865, 
p. 205, pl. xvili, fig. 1,=7vigonodon crebristriata, Conrad, Am. Jl. 
Conch., I, 1865, p. 233,==Margaron (Monocondylaea) crebristriata, 
Lea, Syn., 1870, p. 72, Unio crebristriatus, Sowerby Conch. Icon.., 
XVI, 1868, pl. xev, fig. 517,—Pseudodon crebrisiviatum, Hanley 
and Theobald, Conch. Ind., p.5, pl. ix, fig. 3,=Unio vondembuscht, 
Sowerby Conch. Icon., XVI, pl. xcv, fig. 518. 
Pegu, Reg. Nos. #%22 and 2931, 
52a. Vat. curvata, var. 1. 
Shell having the ventral margin more curved, and generally 
less ovate in shape than in the typical form. 
Hab.—Pegu, Reg. Nos. +220 [Type], 2435. 
52b. Var. peguensis (Anthony),—Monocondylaea peguensis, 
Anthony, Am. Jl. Conch., I, 1865, p. 205, pl. xviii, fig. 2,—Mar- 
garon (Monocondylaea) peguensis, Lea, Syn., 1870, p. 73,—=Pseudo- 
don crebristriatum var. peguensis, Hanley and Theobald, Conch. 
Ind. £876, p55 pl: pe, Ge: 5. 
Zayleyman, Reg. No. 2573. 
Sec. PsEuDopON, Gould, 1884. 
53. Pseudodon (Pseudodon) vondembuschiana (Lea), 
Conrad, Am. Jl. Conch., I, 1865, p. 233,—=Margaritana vondem- 
buschiana, Lea, Proc Am. Phil Soc., I, 1840, p. 288; Tr. Am. Phil. 
Soe Mier Sa2 pis, evil ae. go4 .Obs., [11, 1842, p. 60,, pl. 
xviii, fig. 39,—Margaron (Monocondylaea) vondembuschiana, Lea, 
Syn., 1852, p. 45; 1870. p. 73,—=Monocondylaea vondembuschiana, 
H. and A. Adams, Gen. Rec. Moll., II, 1858, p. 501,—=Monodontina 
buschiana, Conrad, Proc. Ac. Nat. Sci., Philad., VI 1853, pp. 269, 
449,—Unio vonbuschea, Sowerby, Conch. Icon., XVI, 1866, pl. 
li, fig. 269,—Alasmodonta crispata, Mousson, L. and.Stss. W. 
Moll. Java, 1849, p. 97, pl. xvili, figs. I. 2,—Margaritana 
crispata, Paetel, Conch. Sam., III, 1890. p. 173.=.onocondylaea 
planulata, ea, Proc. Ac. Sci., Philad., XI, 1859, p. 187; Jl. Ac. 
Nat. Sci, Philad., 1v; 1859 p. 262, pl. xlii, fig: 742; Obs., VID, 
1860, p. 80, pl. xlii, fig. 142=—=Pseudodon planulata, Conrad, 
Am. Jl. Conch., I, 1865, p. 233.=Microcondylaea planulata, Paetel, 
Conch. Sam., III. 1850, p. 175, —=Margaron (Monocond laea) planu- 
lata, Lea, Syn., 1870, p. 73,=.Margaritana fragilis, Kuster, Conch, 
Cab. Unio, 1862, p. 295, pl. xeviii, fig. 2,—Mzcrocondylaea 
fragilis, Paetel, Conch. Sam., III, 1899, p. 175,=Monocondylaea 
rhombica, Kiister, Conch. Cab. Unio, 1862, p. 304, pl. ¢, fig. 7. 
Sarawak, Reg. Nos , 2248, 3455. 
