ANODONTITUS 1453 



Group of Anodontites ohtusus. 



Shell short, inflated, thin, feebly rayed, rays often broken; 

 base rather full. 



Anodontites oi.tusus (Spix). 



Shell rather short, somewhat obovate, scarcely inflated, thin 

 to subsolid, inequilateral; beaks moderately elevated; dorsal 

 outline arched; anterior end narrowed, rounded; base nearly 

 straight ; posterior end widely rounded or almost squarely sub- 

 truncate ; epidermis somewhat concentrically plicate, sometimes 

 with inconspicuous, radial plicatious, greenish-olive, lurid, of- 

 ten with feeble, wavy or broken rays, especially on the dorsal 

 slope; nacre bluish and greenish-tinted, lurid; muscle scars 

 shallow. 



Length 60, height 40, diam. 25 mm. 



Brazil ; Paraguay. 

 Anodon obtnsns Simx, Test. Fluv. Bras., 1827, p. 30, pi. xxii, 



%• 3- 

 Margarita (Anodonta) obtiisa Lea, Syn., 1836, p. 52; 1838, p. 



31- 

 Anodonta obtiisa Potiez and Michaud, Gall. Moll., 1844, p. 



144. pi. EV, fig. 3. — KusTER, Conch. Cab. Ano., 1853, p. 8, 



pi. II, figs. 3, 4.— MusGRAVE, Phot. Conch., 1863, pi. i, fig. 7. 



— Ceessin, Conch. Cab. Ano., 1875, p. 170, pi. Lvi, figs, i, 2. 

 Margaron (Anodonta) obtiisa Lea, Syn., 1852, p. 51 ; 1870, 



p. 82. 

 Anodon obtusa Sowerby, Conch. Icon., XYH, 1867, pi. xii, 



fig- 39- 

 Glabaris obtmiis Simpson, Syn., 1900, p. c>3i. 

 Anodonta Valenciennes, Coq. Mar. Biv., 1827?, pi. xlviii, 



figs. 3a, b. 



A short, rather thin, subinflated, obovate species. 



Var. juparanns (von Ihering). 



"The specimens described come from the Lagoa Juparana. 

 They differ -from the typical form only in the hind end, the 

 rounded, low extremity of which is separated from the oblique 



