556 



MEMOIRS OF THE CARNEGIE MUSEUM. 



Anal opening slit-liko, closed above; closed part about four to five times as 

 long as the open, the latter separated from the branchial opening b}^ a solid mantle- 

 connection. Branchial opening with small papillse, closed in front by a mantle- 

 connection in the two males and in one of the females, while in the other female 

 this connection is missing (but it may be torn). Palpi moderately large, sub- 

 triangular, with curved lower margins, and the posterior margins united for about 

 one-fourth of their length. 



Gills about equally wide posteriorly, anteriorly the inner is the wider, of the 

 usual shape. Inner lamina of jnner gill entirely connected with the abdominal 

 sac. Non-marsupial gills with scattered interlaminar connections. Marsupium 

 in the middle of the inner gill, leaving about one-fourth of the gill free at the anterior 

 end, and a little less at the posterior. Interlaminar connections interrupted, but 

 their arrangement cannot be clearly seen, since no barren females are at hand. 



Glochidium (text-fig. 4, m, p. 469 ) subtriangular, with a point at about the 

 middle of the lower margin, and with hooks of the usual shape, but rather short. 

 L. and H. about 0.24 mm., hooks 0.05 mm. Thus the glochidium is rather small. 



33. Castalia hanleyana Sowerby (1869). 



Castalia hanleyana Sowerby, XVII, 1869, PL 1, f. 5. 

 Tetraplodon hunleyanus Von Ihering, 1910, p. 127. 



Type-locality. — Unknown. 



Other Localities. — Rio Araguaya, Ilha Bananal, Goyaz, Brazil (Von Ihering); 

 State of Para, Brazil (Von Ihering) . 



New Locality. — Sand bar of Rio Tapajos, Santarem, Para, Brazil (J. D. Hase- 

 man coll., December 6-12, 1909). Two odd valves (right and left). 



Distribution. — It should be noted that this species is found, where also acuti- 

 costa occurs, in the Rio Araguaya and the Rio Tapajos. 



My two valves agree well with the account given by Von Ihering, and with 

 Sowerby's figure, but are smaller than the latter. 



Remarks. — According to Von Ihering, the beaks are at 30 to 33 pr. ct., while my 

 specimens show lower figures. But this fact may be due to a different way of 

 measuring. The shell is characterized by high beaks and its high, triangular (not 



