G12 MEMOIRS OF THE CARNEGIE MUSEUM. 



Anodontites patagonicits Haas, 1916, pp. 25, 54. 



As we have seen above, Anodon trapezeum Spix (1827) should be stricken from 



the list of sjTionyms. This is a different species, differing chiefly by the narrow 



prismatic border. The other references given by Simpson all certainly belong here, 



and the following names have been used for this species : 



Anodonta latomarginata Lea (1834). 



Anodonta membranacea D'Orbigny (1843). 



Anodonta solida Kuester (1853). 



Anodonta ^iruguayensis Lea (1860). 



Anodonta sinuosa Clessin (1873). 



Anodonta serpentina Clessin (1876). 

 In addition: 



Glaharis bergi Von Ihering (1893 p. 118), introduced for sinuosa Clessin. 

 But the following forms also belong here as synonyms : 



Anodon crassus Swainson (1823); Simpson, 1914, p. 1406. Simpson says: this 

 species is "close to A. palagonicus, but I have never seen a specimen of that 

 species quite so elongated or so pentagonal as the figure." The dimensions 

 are: L. 80 mm., H. 52 mm. = 65 pr. ct. of length. Diameter 32 mm. = 40 pr. ct. 

 of length. These figures agree well with the dimensions of m}^ series of speci- 

 mens from San Isidro, some of which are even more elongated (height falling 

 as low as 60 pr. ct. 



Anodonta wymani Lea (1860); Simpson, 1914, p. 1407, who says: "More elongated 

 and more richly colored than A. patagonicus." The elongation is even greater 

 than in A. crassus (Height = 63 pr. ct. of length), but it still remains within 

 the limits of variation of my set from San Lsidro. Some of the latter un- 

 doubtedly are ivymani in every respect. The color is no reliable character, 

 being very variable in A. patagonica. 

 I am unable to form an opinion as to A. sirionos D'Orbigny (1835) (= ferrarisi 



D'Orliigny, 1835). It certainly is nearh' related to A. patagonica, but, according 



to the original description, is distinguished by a rough and concentricall)^ and 



lamellarly striate epidermis. I have no specimens corresponding to this form. 

 Type-locality. — Rio dc la Plata and Patagonia. 

 Other Localities. — Rivers of Uruguay between Montevideo and Buenos Aires 



(D'Orbigny, membranacea); Rio Miguelete, Montevideo, Uruguay (Haas); Arroyo 



S. Jose, Uruguay (N. W. of Montevideo) (Corsi, uruguayensis); LIruguay River 



(Lea, uruguayensis, mjmani); Rio de la Plata (Haas); Rio de la Plata, Buenos 



Aires, Argentina (D'Orbigny, membranacea); Rio Parana fLea, latomarginata); 



