NO. 1205. SYNOrSIS OF THE xaijdes—stmpson: 581 



*Unio (Monocondi/la'a) cambojensis Sowkkby, Concli. Icon., XVI, errata. 

 *Pseudodon cambojensis Morelet, Ser. Conch., IV, 1875, p. 336. 



* Unio Imnellatus Hanley and Theobald, Couch. Intl., 1876, j>. .5, pi. i.\, fig. 6. 

 *Umo vaf/ulu8 Fischer, Bull. Soc. Autun., IV, 1891, p. 22.3. 



Siain. 



(Group of Hyriopsh veWiuzeni.) 



Shell vsouiewhat iuflated, rather thin, rounded behind, winged; epi- 

 dermis dark brown with numerous green rays; nacre iridescent, bluish 

 white; anterior scars irregular, rather small; posterior scars rounded; 

 ])seu(locar(linals elongated, one in each valve, in the right valve there 

 is a secondary ludimental one; laterals elongate, arcuate, one in the 

 right valve and two in the left. 



tHYRIOPSIS VELTHUZENI Schepman. 



* Unio velthuzeni >Schepman, Notes from Leyden Mas., XVII, 1895, p. 160, pi. iv, 



figs. 1, 1«— 1 Drouet, Jl. de Conch., XLV, 1897, p. 124. 



Mandai River, Borneo. 



(Group of Syriopsis schlegeli.) 



Shell rather thin, slightly winged behind, narrowly rounded before 

 and angled at umbonial slope; posterior ridge high and rounded, beaks 

 rather low ; epidermis rough, blackish ; hinge line curved in front, 

 straight behind; pseudocardinals generally entire; plications below the 

 laterals faint; nacre dull, lurid purplish or lead color. 



tHYRIOPSIS SCHLEGELI von Martens. 



* Unio schlegeli von Martens, Mai. Blatt., VII, 1861, p. 55. — * Kobelt, Abh. 



Senck, Nat. Ges., XI, 1879, p. 421, pi. xiv.— * vox Martens, Nov. Conch., V, 

 1879, p. 192, pi. CLViii, figs. 4, 5.—* von Ihering, Abh. Senck, Nat. Ges., 

 XVIII, 1893, p. 156. 



* Barhala schlegeli PzETEL, Conch. Sam., Ill, 1890, p. 175. 



Japan. 



Subgenus CAUDICULATUS Simpson, 1900. 

 (Type, TJnio caudtculatus von Martens.) 



Shell oval, inflated, slightly posteriorly winged, with a well-developed 

 posterior ridge, and above it a deep, wide furrow ending in a broad, 

 well-defined notch on the posterior slope; one pseudocardiual in the 

 right valve and two in the left; two laterals in the left valve and one 

 in the right. Animal unknown.- 



HYRIOPSIS CAUDICULATUS Von Martens. 



''Unio caiidiculatus von Martens, Mai. BL, XIV, 1866, p. 16.—* Schepman, Notes 

 Leyd. Mus., XVIII, 1896, p. 140.—* Drouet, J. de Couch., XLV, 1897, p. 126. 



* Unio infrarostratus Schepman, Notes Leyd. Mus., XVII, 1895, p. 161, pi. iv, fig. 2. 



Borneo. 



'According to the photographic figure this shell very closely resembles Unio ala- 

 tus Say. 



■'I am in doubt as to the relationship of this species. 



