Mocvrrm A CAT AUG beans DAE ASLTATIC 
NATADES IN. THE COULMerhLON OF -T LE 
ENDLANS: MUS E-UM , “Qian e UsiieaA,. «Ww ITE 
Dioer LPTLONS OF Whe oe CLES. 
By TB. PRESTON, SEGAL. 
Plate Vit: 
In compiling the following catalogue the scheme generally 
followed is that used by Mr. C. T. Simpson in his valuable work 
‘Synopsis of the Naiades, or Pearly Freshwater Mussels”! ; 
occasionally however the author, after examining the large series 
of specimens not only in the Indian, but also in the British Museum, 
has had to deviate from that system, but as far as possible 
Simpson's work has been incorporated in the present catalogue. 
The author’s thanks are especially due to Mr. Edgar A. Smith, 
I.S.0., of the British Museum, whose unrivalled knowledge and 
great courtesy in placing specimens in his hands for examination 
have largely helped him in his labour. 
Three extra-Indian species are figured in the plate that accom- 
panies this catalogue ; the new Indian forms here described will 
be figured later in a volume of the ‘‘ Fauna ot British India.” 
Fam. UNIONIDAE. 
Subfam. UNIONINAE, Swainson, 1840. 
Gen. Hyriopsis, Conrad, 1853 
1. Hyriopsis bialatus, Simpson, Syn. Naiades, Proc. U.S. 
Nat. Mus., XXII, p. 579,—=Uwmio delphinus, Grunner, Arch. fiir 
Naturg., I, 1841, p. 276, pl. ix, figs. 1, 1a-c,—Margaron (Unio) 
delphinus, Lea, Syn., 1852, p. 19; 1870, p. 28,—=Unio megapterus, 
Morelet, J. de Conch., XXI, 1863, p. 159. 
Siam (Russel coll.), Reg. Nos. 25#2, 5032; Pahang River, 
Malay Peninsula (Dr. Cantor), Reg. No. +°»:; Cambodia, Reg. 
2. Hyriopsis cumingii (Lea), Simpson, Syn. Naiades, Proc. 
U.S. Nat. Mus., XXII, p. 579,—=Unio cumingw, Lea, Proc. Ac. 
Wat. Sei. Philad,, VII, 1852, p, 54; Lea, Jl. Ac. Nat..Scr, Phitad, 
IV, 1860, p, 240, pl. xxxv,, fig. 120,—Margaron (Unio) cumingit, 
Lea, Syn., 1852, p. 19; 1870, p. 28. 
Shanghai Market, Reg. No. +95«; Shanghai, Reg. No. sos, 
1 Proc. U.S. Nat. Mus., Washington, D.C., XXII, 1900, pp. 501—1044. 
