1913.] NATURAL SCIENCES OF PHILADELPHIA. 659 



the juncture of the outer and basal margins; columella and parietal 

 margins continuous, forming a raised ledge across the parietal wall. 



Alt., estimated in full, 4.1, diam. 2.15, length of aperture 1.15 mm. 



Two specimens were taken with the last near the head of Papary 

 Lake. 



This species differs from /. souleyetanus Pils. by its darker color, 

 fewer whorls and slightly smaller size. It is the second species of 

 the genus to be taken, the other, I. souleyetanus Pils., having been 

 taken at Rio Doce, state "of Espiritu Santo, in southern Brazil. 

 In his description Dr. Pilsbry remarks, ''It is probably a straggler 

 from the fauna of eastern Brazil, of which little is known," a shrewd 

 deduction which the discovery of 7. pUshryi confirms. The species 

 is named for Dr. H. A. Pilsbry, who characterized the genus. 



AMPULLARIID^. 



Genus AMPULLARIA Lamarck. 

 Ampullaria gigas Spix. 



Testae, fluv. bras., p. 1, tab. 1, 2. 



Ten specimens were taken at Itacoatiara and one large and four 

 half-grown specimens were sent from the Goeldi Museum, the first 

 taken on the Island of Mexiana, two at Baiao on the right bank of 

 the Rio Tocantins, and two at Arumanduba, Parana de Almeirim. 

 Ampullaria figulina Spix. 



L.C., p. 4, tab. iv, fig. 4. 



Dead shells of this species were taken quite commonly on the 

 shores of Lake Estremoz and three specimens taken in the Igarape 

 de Paituna, near Monte Alegre, Fazenda Ponto, and eight taken 

 ''in the wet plains near Arumanduba," Parana de Almeirim, were 

 sent from the Goeldi Museum. 

 Ampullaria insularum Orbigny. 



Voyage dans rAmer. ]Merid., p. 371, pi. 51, figs. 1, 2. 



This shell was rather common in the streams about Papar>^, asso- 

 ciated with the commoner A. testudinea Rve., and the Goeldi Museum 

 sent seven specimens taken in the Rio Nhamunda at Fazenda Paraiso, 

 near Faro, six from Boim e Pinhel, on the right bank of the Rio 

 Tapajoz, three from Monte Alegre, Igarape Pucii, and five from 

 Arumanduba, Parana de Almeirim. Von Ihering (Anal. Mus. Nac. 

 Bs. As., VI, Aug. 3, 1898) considers this species synonymous with 

 A. gigas Spix. All shells examined, while showing the same general 

 form and deep sutures, were easily separated by the much lighter 

 weight of the shells and the more open umbilicus. 



