NO. 1205. SYXOPSIS OF THE X.I r.lDFXSIMPSOX. 851 



somewhat blurred grantilous laterals; right valve with a single blunt 

 pseudocardinal, the hinge line in front of it being excavated, and a 

 curious blurred lateral which is sometimes slightly split up; beak cav- 

 ities shallow; dorsal scars few; nacre whitish. Animal unknown. 



(Group of Ptycliob ranch us pfisteri.} 

 Characters as in the genus. 



tPTCHORHYNCHUS PFISTERI Heude. 



" I'nio pfvttm HEUDE, Jl. de ConcL., XXII, 1874, p. 112; 'Conch. Fluv. Nank., I, 

 1875, pi. i, fig. L * P.ETEL, Conch. Sam., Ill, 1890, p. 163. 



PTYCHORHYNCHUS PFISTERI var. INSPIRATUS Heude. 



* Unio pfisteri var. inspiratns HEUDK, Conch. Fluv. Nank., II, 1877, pi. xiv, fig. 28. 



*PyETEL, Conch. Sam., Ill, 1890, p. 155. 



Nankin River, China. 



t PTYCHORHYNCHUS MEDIASTINUS Heude. 1 



y Unio mcdiastinus HEUDE, Concli. Fluv. Nank., VIII, 1883, pi. LXIII, fig. 123. 



* P.ETEL, Conch. Sam., Ill, 1890, p. 158. 



China. 



(Group of Ptycliorliynchus apicellatus.) 



Shell subrhomboid, more or less biangulate behind. 



PTYCHORHYNCHUS APICELLATUS Heude. 



* t'nio apiceUatits HEUDE, Conch. Fluv. Nank., VIII, 1883, pi. LXIII, fig. 126. 

 China. 



PTYCHORHYNCHUS SCHOMBURGIANUS Heude. 



* Unio achombitrgianus HEUDE, Jl. de Conch., XL, p. 314; * Conch. Fluv. Nank., IX, 



1885, pi. LXXII, fig. 139.* PJETEL, Conch. Sam., Ill, 1890, p. 167. 



Isle of Hainan, China. 



PTYCHORHYNCHUS INCERTUS Simpson. 



* Unio compressus HEUDE,- Conch. Fluv. Naiik., Ill, 1877, pi. xxiv, fig. 52. 



* P.ETEL, Conch. Sam., Ill, 1890, p. 148. 



* Unio murinus HEUDE, Couch. Fluv. Naiik., VIII, 1883, pi. LXII, fig. 121. 



* Unio morinua PJETEL, Conch. Sam., Ill, 1890, p. 160. 



China. 



Genus VIRGUS, Simpson, 19OO. 

 (Type, Unio beccarianits Tapperone Cauefri.) 



Shell rather solid, elongated, inequilateral, compressed, rounded in 

 front, nearly straight below, the dorsal line as far back as the hinder 



1 Probably ouly a variety of I', pfisteri. 



2 The name compressits has been twice used previously for a Unio. I change it here 

 to incertus. 



