1913.] NATURAL SCIENCES OF PHILADELPHIA, 661 



of a small affluent of the Rio Jary near the great falls" near St. 

 Antonio da Cachoeira were sent from the Goeldi Museum. They 

 seem to fall into this species, although they are proportionally 

 slightly narrower than is typical for the species. 



Genus MAEISA Gray. 



Marisa cornu-arietis Linne. 



Syst. Nat., X, p. 771, No. 590. 

 A single specimen of this species, taken at Alcobaga, on the Rio 

 Tocantins, was sent from the Goeldi Museum. 



PHYSID^. 



Genus PHYSA Draparnaud. 

 Physa rivalis (Maton and Rackett). 



Bulla rivalis M. and R., Trans. Linn. Soc. London, VIH, 1807, p. 126, pL 



4, fig. 2. 

 Physa sowerbyana Orbigny, in Sagi'a, Hist. fis. polit. e nat. de la Isla de Cuba, 



Moluscos, p. 101, pi. 13, figs. 11-13, 1845. 



About fifty specimens were taken in an artificial lake in the park 

 in front of the Cathedral of Para, half a dozen in Papar}^ Lake, and a 

 single dead specimen taken at Ceara-Mirim seems to be the same. 



Physa sp. undet. 



Forty or fifty young specimens taken at Maranhao seem somewhat 

 different from the preceding, but may be the same. They are too 

 young to diagnose with certainty. 



PLANORBID^. 



Genus PLANORBIS ISIiiller. 



Planorbis anatinus Orbigny. 



P. anatinus (Planorbe des Canardes) Orb., Voyage, V, pt. 3, p. 361, pi. 45, 

 figs. 17-20. 



About twenty-five specimens were taken with Physa rivalis in the 

 artificial lake in Para. 

 Planorbis cultratus Orbigny. 



In Sagra, I.e., p. 105, No. 115, pi. xiv, figs. 5, 8. 



Half a dozen specimens were taken near the mouth of the principal 

 affluent of Lake Papar^^ . This is the southern known limit for the 

 species. 



Planorbis cimex Moricand. 



Thirteen specimens were taken with the preceding. 

 Planorbis guadeloupensis Sowerby. 



Genera of Shells, Planorbis, fig. 2, (1824?). 



This shell was taken commonly with the preceding two near Lake 



