PILSBRY: NON-MARINE MOLLUSCA OF PATAGONIA. 557 



LITTORIDINA AUSTRALIS (d'Orbigny). 



(Plate XLIr, Figs. 3-8.) 



Paludina australis d'Orb., Mag. de Zool., 1830, p. 30. 

 Paludestrina australis d'Orb., Voyage, p. 384, pi. 48, figs. 4-6 (Bahia Blanca 

 and Bahia de San Bias, Patagonia, on water plants and mud covered 

 by each tide ; also at Montevideo) ; von Ihering, Nachrichtsblatt, 

 XXVII, 1895, p. 123, anatomy (Rio Grande do Sul and Sao Paulo) ; 

 von Martens, Malak. Blatter, XV, 1868, p. 192 (Porto Alegre). 

 Melania dubiosa Clessin. 



d'Orbigny gives the dimensions, length 6, diam. 3 mm., whorls 7. Fig. 

 7, drawn from a specimen from Bahia Blanca, the type locality, is of this 

 size. Some examples are narrower (fig. 6), and others much larger, length 

 8.5 mm. (fig. 5). The whorls are almost flat except in the largest shells, 

 where the last whorl is convex. Under a strong lens very faint spiral 

 striae may be seen on most examples. Figures 5-7 represent bleached 

 shells from Bahia Blanca, the type locality, received from Dr. von 

 Ihering. 



At Montevideo, in a creek in the Prado, the shells taken by Dr. Rush 

 are large, olivaceous, with noticeably more convex whorls. They measure : 



Length 8.3, diam. 4, length of aperture 3.5 mm.; whorls 8. 



8.2 " 3.9 " " 3.2 " " y#. 



8-4 3-9 " 3-3 " 8#. 



In a small spring back of the Cerro, Montevideo, the shells are similar 

 but smaller, about 5 mm. long with 6% whorls. 



Shells from Rio Grande do Sul, sent by Dr. von Ihering, are about 6 

 mm. long, 2.3 to 2.9 mm. in diameter. The more slender shells are less 

 numerous than the stouter ones, and some are transitional in shape. The 

 color varies from dark to pale olive (Plate XLI<:, figs. 3, 4, 8). A small 

 form has been sent also from Ilha Comprida, near Iguape, on the Sao 

 Paulo littoral. 



Melania dubiosa Clessin, judging from specimens sent from S. Leopoldo, 

 State of Rio Grande do Sul, by Dr. von Ihering, is identical with the 

 large form of L. australis noticed above from Montevideo. 



