ortmann: south American naiades. 



597 



S. Francisco-drainage); Bodegas, and Rio Daule, Ecuador (C.ermain) (Pacific- 

 drainage, near Ctuayaqnil). 



Nciv Locality.— Lagoa Saclio CJrande, ("idadc da Barra, Baliia, Brazil (J. D. 

 Haseman coll., December 24, 1907). . One young specimen. (S. Francisco- 

 drainage). 



Another, larger specimen is in the Carnegie Museum, from the Holland Collec- 

 tion, labeled "Brazil." 



Distribution. — Known from the drainages of Rio Paraguassu and Sao Fran- 

 cisco. Von Ihering gives a possible variety, similar to the var. hohenackeri, from 

 Rio Mucury, Bahia (southern jiart) (1890, p. 161), and another variety (juparana, 

 1910, p. 131) from Lagoa Juparana of Rio Doce, Espirito Santo).-" The form 

 is not known from the basin of the Amazon. So much more astonishing is Germain's 

 record of this species from the Pacific slope in Ecuador. I cannot discover any 

 differences in these specimens, but attention should be called in this connection 

 to A. aff. pastasanus of Haas (1916, pp. 34, 56, PI. 2, fig. 1) which comes from the 

 identical localities (Rio Daule and Bodegas in Ecuador). The latter, however, 

 is more elongated than Germain's figure of obtum, and cannot be the same. 



Simpson also cites Paraguay, but I do not know on what authority. 



After what Wagner and ^' on Ihering have said, it is perfectly clear that litumta 

 is the young stage of obtum, and my larger specimen shows, near the beaks, the 

 juvenile character of broken and oblique rays. Hupe says that liturata is less 

 swollen than o6^Msa, "while Simpson (1914, p. 1454) states the opposite, that it is 

 more inflated (possibly slip of the pen). Of my two specimens it is the smaller 

 one, with /(7»ra/a-color-markings, which is the more swollen. 



Measurements. 



3. Group of Anodontites trapezea. 



Shell subcirciilar, but distinctly oblique, short and high. Epidermis dull, 

 densely, concentrically, lamellarly wrinkled. Prismatic border moderate, or narrow, 

 of nearly equal width. 



The subcircular shape and the dull, cloth-like epidermis arc found in no other 

 group combined. 



■'> In 1010 (p. 131) he says that specimens from U'u< Mucnry :\v(\iiipiirnn(i. 



