8 PEOCEEDINGS OF THE NATIONAL MUSEUM vol. 7u 



is Rio de la Paila, Paila, Republic of Colombia. Comparison with 

 the type of A. colomhlensis Marshall proves beyond doubt that Ort- 

 mann's specimens belong to that species and not to A. crispata Bru- 

 guiere. Figures on Plate 2 of the present paper show that A. crispata 

 Ortmann is exactly like A. colombiensis in form and sculpture and 

 radically different from the true A. crispata Bruguiere. 



Ortmann gave as type locality " South America." This was not 

 explicit enough, as Bruguiere recorded the type locality as " Rivieres 

 de la Guyanne." 



The localities cited by Ortmann, except Cayenne (Lea), are to be 

 rejected. They were Amazon River (Sowerby, reticulatus) and Rio 

 de la Paila, United States of Colombia — a tributary of the upper Rio 

 Cauca of the Rio Magdalena drainage. Simpson's statement that 

 A. crispata is " widely distributed in tropical South America " is to 

 he rejected also, for at the present time crispata is known only from 

 Guiana (and in that region probably only from the vicinity of 

 Cayenne in French Guiana). 



From a nomenclatorial standpoint Ortmann made a valuable sug- 

 gestion when he pointed out in that paper that as crispata is i\\<? type 

 of the genus Anodontites it must necessarily be the type of the section 

 Anodontites s. s. Simpson (1914, p. 1403) grouped a number of 

 species in a section Anodontites s. s., the first group under the sec- 

 tional description being the group of A. patagonicus and the first 

 species in the group being also patagonicus. On page 1414 crispatus 

 is the first species in the group of A. crispatus. Although both these 

 groups and several others were placed in the section Anodontites s. s., 

 rthe fact that patagonicus heads the list makes it appear that Simpson 

 intended that species to rank as the type of the section. 



Ortmann (1921, pp. 587, 588) attempts to correct Simpson's (1914) 

 division of Anodontites in three sections, viz, Anodontites s. s., Sty- 

 ganodon von Martens (1900), Virgula Simpson (1900), but because 

 of his erroneous identification of colomhiensis Marshall with crispata 

 Bruguiere the attempt resulted in serious errors. Ortmann says 

 (1921, p. 588) : 



St.i.'fjanodon is well char;i(teri:<efl by the t'lDidermis ; but imfortuuately the 

 •type of the genus {Anodontites crispata) undoubtedly belongs to Styrjanodon, 

 having an enidermi.s (thick, dark, rough, somber colored) which represents an 

 extreme deveiopnient of the stuyanodon structure; in other characters uiso 

 A. crisputa is closely allied to A. tcmbiicosa, the type of Slyyanodon. 



It is clear that, on the one hand, Anodontites (sensu strictiore) must be 

 used for cri'<p(ita and, on the other hand, that Styganodon is a synonym of this, 

 the tj'pe of the latter being closely related to crispata. This necessitates a 

 rearrangement of the sections and a revision of their nomenclature. 



The well-known Anodontites teiiehricosa Lea is the type of Styg- 

 anodon. Its features are so different from those of A. crispata that 



