ortmann: south American naiades. 



571 



A key to the three known species has been given by \'on lliering (1910, p. 115). 

 Two of the species are from the Parana-drainage, and one is from a coastal river 

 in eastern Brazil, the Rio Paraguassii in Bahia. 



42. FossuLA fossiculifera (D'Orbigny) (1835). 

 Section of gills: Plate XLVIII, fig. 6. 

 Monocondylcca fossiculifera D'Orbigny, 1<S43, p. 614, PI. SO, figs. 5-7. 

 Unio fossiculiferus Sowerby, XVI, 1868, PL 96, fig. 521. 

 Fossula fossiculifera Von Ihering, 1893, p. 64, PI. 3, fig. 2; Nehring, 1893, p. 164; 



Simpson, 1900, p. 914; Von Ihering, 1910, p. 115; Simpson, 1914, p. 1396. 



Type-locality.— Rio Parana, Iribucua, above Corrientes, Argentina. 



Other Localities.- -Rio Parana and lower Rio Tiete, Sao Paulo, Brazil (\'on 

 Ihering); Rio Piracicaba, Piracicaba, Sao Paulo, Brazil (Von Ihering) (Nehring). 



Localities Represented in the Carnegie Musewm.-Rio Piracicaba, Piracicaba, 

 Sao Paulo, Brazil (Von Ihering donor). One specimen. Rio Tiete, Salto de 

 Avanhandava, Sao Paulo, Brazil (J. D. Haseman coll., September 15, 1908). One 

 specimen. Rio Tiete, Salto das Cruzes, Sao Paulo, Brazil (J. D. Haseman coll., 

 September 22, 1908). One female with soft parts. Rio Tiete, Itapura, Sao 

 Paulo, Brazil (J. D. Haseman coll., September 28, 1908). One female with soft 



parts. 



Distribufion.—Rio Parana and its tributaries from Argentina to Sao Paulo, 



Brazil. 



This species has been well figured by D'Orbigny and Von Ihering, and has 

 been well described by the latter. No further details need to be supplied. 



Measurements. 



According to Von Ihering the height varies from 80 to 85 pr. ct., while in D'Or- 

 bigny 's specimen it is 77 pr. ct. 



^n«^o//(y.— Partially described by Von Ihering (1893. p. 65) for the male. I 

 am able to supplement this from two barren females at hand. 



Anal opening entirely open, very large, with smooth inner edge, very faintly 

 crenulated in the lower part, separated by a solid mantle-connection from the 



