I2IO CAIJvONAIA 



Genus CALLONAIA Simpson, 1900. 



Callonaia Simpson, Syn., 1900, p. 867. 



Shell triangular, thin, inflated, with very high, full beaks 

 which appear to be without sculpture; a very high, sharp pos- 

 terior ridge extends to the base of the shell, above which it is 

 decidedly truncated ; anterior end somewhat pointed above, 

 rounded below ; ligament very short ; surface nearly smooth, 

 but somewhat sulcate anteriorly ; epidermis bright, greenish- 

 yellow, shining; hinge line strongly arched; teeth compressed, 

 high ; two pseudocardinals in each valve, all interlocking and 

 side by side; one lateral in the right valve and two in the left, 

 a little ragged and granularly, vertically striate; beak cavities 

 very deep, not compressed ; muscle scars superficial ; nacre 

 brilliant, bluish-white, radiately striate posteriorly. 



Animal unknown. 



Type, Castalia duprci Recluz. 



Callonaia DurREi (Recluz). 



Shell subtriangular, inflated, rather thin, slightly inequilater- 

 al ; beaks very high and full ; ligaments short and broad ; hinge 

 line much arched ; upper anterior outline from the beaks for- 

 ward obliquely truncate, below this it is narrowly rounded and 

 the anterior base is slightly cut away ; base line nearly straight ; 

 posterior basal point sharp ; surface with delicate growth lines, 

 which are stronger anteriorly ; epidermis pale yellowish-green, 

 shining, darker and dull-colored on the ])osterior slope ; nacre 

 slightly thickened in front. 



Length 70, height 56, diam. 42 mm. 



Length 68, height 53, diam. 35 mm. 



Great lakes of Para, Brazil. 

 Castalia diiprei Recluz, Rev. Zool. 1843. p. 305, pi. xxxv. — 



Chenu, Man., 1859, II, p. 149, fig. 738. 

 Unio duprci Catlow and Reeve, Conch. Nom., 1845, p. 58. 

 Margaron (Prisodon) duprci Lea, Syn., 1852, p. 18; 1870, 



p. 27. 

 Callonaia duprci Simpson, Syn., 1900, p. 867. 

 Castalia dolahella Sovverby, Conch. Icon.. XVIT, 1869, pi. iii, 



figs. i3«. 13^ 13^- 



