NO. 1205. SYNOPSIS OF THE NAIADES SIMPSON. 831 



PHYSUNIO CROSSEI Deshayes and Julien. 



"Unto crosaei DESHAYES and JULIEN, N. Arch. Mus., X, 1874, p. 124, pi. vi, figs. 

 5-7.* P.ETEL, Conch. Sam., Ill, 1890, p. 149. 



Cambodia; Cochin China. 



t PHYSUNIO MICROPTERUS Morelet. 



* Unio micropterus MORELET, Jl. do Conch., XIV, 1866, p. 63;. Ser. Couch., IV, 1875, 



p. 349, pi. xv, fig. 7.* P.ETEL, Couch. Sain., Ill, 1890, p. 158. 



Siam; Cambodia. 



PHYSUNIO SEMIALATUS Deshayes and Julien. 



* Unio semialatus DESHAYES and JULIEN, N. Arch. Mus., X, 1874, p. 123, pi. vi, figs. 



1,2.' 



Siain; Cambodia. 



t PHYSUNIO CAMBODIENSIS Lea.- 



* Unio camlodiensis LEA, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 103; Jl. Acad. 



N. Sci. Phil., Ill, 1857, p. 313, pi. xxx, fig. 28; Obs., VI, 1857, p. 33, pi. xxx, 

 fig. 28. 



* Margaron (Unio) camlodiensis LKA, Syn., 1870, p. ,42. 



Takroug River at Korat, Cambodia 



Section LENS Simpson, 1900. 

 (Type, Unio eximius Lea.) 



Sbell sublenticular ; three laterals of left valve distinct; cavity of tbe 

 beaks compressed. 



t PHYSUNIO EXIMIUS Lea. 



* Unio eximius LEA, Pr. Ac. N. Sci. Phila., VIII, 1856, p. 93; Obs., VI, 1857, 



p. 14, pi. xxv, fig. 8; Jl. Ac. N. Sci. Phila., Ill, 1858, p. 294, pi. xxv, fig. 8. 

 * VON MARTENS, Pr. Zool. Soc. Lond., 1860, p. 15. * SOWERBY, Conch. Icon., 

 XVI, 1868, pi. LXXXIX, fig. 481. * P.ETEL, Couch. Sam., Ill, 1890, p. 152. 



* Margaron ( Unio) eximius LEA, Syn., 1870, p. 28. 



Unio semiquadrata SOWEKBY, Conch. Icon., XVI, 1866, pi. XLVIII, fig. 258. 



* Unio semiquadratus P.ETEL, Conch. Sam., Ill, 1890, p. 167. 



Siam; Cambodia. 



PHYSUNIO VELARIS Sowerby. 



* Unio relaris SOWERBY, Conch. Icon., XVI, 1868, pi. LXXII, fig. 368. 3 * P^TEL, 



* Couch. Sam., Ill, 1890, p. 171. 



Assam. 



1 Fischer believes that the above equals U. micropterus Morelet (Cat., p. 142). I 

 feel sure he is wrong, and that this is a valid species. 



2 1 have only seen the type of this, a very young shell, but it probably belongs to 

 the grai-idus group. 



? A compressed shell of a uniform yellow color, probably only a variety of eximius. 



