1432 ANODONTTTES 



\'ar. cygiucformis (Pilsljry). 



Shell irregularly long- obovate, rather delicate and thin, not 

 inflated ; epidermis greenish or olive-green. 



Length 136, height 68, diam. 37 mm. 

 Glabaris trapesialis var. cygnccformis Pii,sbry, Pr. Ac. N. Sci. 



Phila.. 1896, p. 563, pi. XXVI, fig. 4, 5. — Simpson, Syn., 1900, 



P- 925- 



The posterior end is drawn out and bluntly pointed. 



Anodontites r.\diatus (Spix). 



Shell irregularly oblong, thin and fragile, compressed, pel- 

 lucid, inequilateral ; dorsal outline straight ; anterior end nar- 

 rowed and rounded ; base lightly curved in front, very full 

 behind the middle, the outline curving up to a blunt point at 

 the posterior end above the median line ; dorsal slope obliquely 

 truncate ; beaks full, slightly elevated ; surface densely, con- 

 centrically striate; epidermis glaucous-green with broad, reg- 

 ular, faint, darker rays ; nacre bluish. 



Length 65, height 33 mm. 



Brazil. 

 Anodon radiatns Spix, Test. Fluv. Bras., 1827, p. 31, pi. xxiii,, 



fig. I. 

 Margarita (Anodonta) radiata Lea, Syn., 1836, p. 51. 

 Anodon radiata Catlovv and Rre\'E, Conch. Nom., 1845, P- 67. 

 Margaron (Anodonta) radiatns Lea, Syn., 1870, p. 83. 

 Cilabaris radiata von Ihei^ing, Arch, fiir Nat., 1893, P- i^S- 

 Glabaris radiatns Simp.son, Syn., 1900, p. 925. 



The shell figured is evidently quite young, and Wagner 

 states that the margins are membranous. It may be only the 

 young of a variety of A. trapesialis, but it is remarkably full 

 at the base behind the middle, and I have never seen any shells 

 of that species so rayed. 



Anodontites simpsonianus (Pilsbry). 



Shell subelliptical or slightly obovate, subinflated or in- 

 flated, solid, inequilateral; beaks long, full and elevated; pos- 

 terior ridge well developed, rounded, ending in a blunt point 



