1448 ANODONTITES 



or slightly oblique. Epidermis olive-green, lighter on the pos- 

 terior portion and dark brown anteriorly. Nacre iridescent 

 blue. The prismatic margin is narrow. Impressions of the 

 posterior adductors are under and partly behind the sinulus ; 

 those of the anterior adductors are very small. The sculpture 

 is peculiar. On the anterior portion are numerous radiating 

 striae, while the epidermis, where it remains, shows fine, radial 

 wrinkles, which are very short on account of being interrupted 

 by the lines of growth. 



I have before me two single valves of almost the same 

 length. The length of the hinge is 48 mm. The beaks are 19 

 mm. from the end of the hinge, showing an umbonal index of 

 39.60/100. 



Length 79, height 45, diam. 29 mm." (von Ihering). 



Type locality. Fazenda do Sacremento, Municipio de San 

 Domingos do Prata in the State Minas, and undoubtedly in 

 the region of the Rio Doce. 

 Glabaris dulcis von Thertnc, Abb. Senckenb. Ges., XXXII, 



1910, p. 132, pi. 12, figs. ^a-h. 



Section Styganodon von Martens, 1900. 



Styganodon von Martrns, Biol. Cent. Am., Moll., 1900, p. 



525- 



Shell subrhomboid, with a thick, dark, rather rough, sombre- 

 colored epidermis, which is sometimes faintly rayed, nacre 

 lurid, shaded green ; animal imknown. 



Type, Anodonta tcnchricosa Lea. 



Group of Anodoiitites tcncbricosiis. 

 Shell elongate, slightly inflated ; base incurved. 



Anodontitks tunebricosus (Lea). 



Shell long rhomboid or trapezoid, somewhat inflated, rather 

 solid, especially wdien old, inequilateral ; beaks but slightly ele- 

 vated ; anterior end narrowed, rounded, generally more or less 

 cut away below; hinge line slightly arched; base straight or a 

 little incurved medially ; posterior end somewhat obliquely 



