662 PROCEEDINGS OF THE ACADEMY OF [DeC, 



Papary and was not rare on the shores of Lake Estremoz, all specimens 

 having been taken dead. So far as is known to the writer, this 

 species has not been taken before in South America, and this is the 

 southern known limit for the species. 

 Flanorbis stramineus Dunker. 



Conchylien Cabinet, p. 4, pi. v, fig. 7a. 

 Specimens were taken with the preceding at Papary Lake, at 

 Ceara-Mirim, and at Ceara. There are about half a dozen very 

 similar forms of Planorbis described from South America, not figured 

 or imperfectly figured, quite possibly reducible to one or two species. 

 Planorbis stramineus Dunker seems to be the first of these to be 

 described. 



Planorbis depressissimus Moricand. 



Mem. de la Soc. de Phys. et d'Hist. Nat. de Geneve, VIII, 1S39, p. 143, pL 

 3, figs. 10, 11. 



One specimen of this species "from the Coast Region of Ceara" 

 was sent by Mr. Rocha. 



Planorbis peregrinus Orbigny. 



Magazin de Zoologie, 1835, p. 26; Voyage, p. 348, pi. 44, figs. 13-16. 

 One specimen ''from the Coast Region of Ceara" was sent by 

 Mr. Rocha. 



Segmentina paparyensis n. sp. PI. XXVI, figs. 9, 10, 11. 



Shell dextral, broadly, rather deeply umbilicate, rather solid, 

 planorboid, everywhere sculptured with minute, retractive, sharp 

 costulse, irregularly sized and spaced, the interspaces being broader, 

 and showing on the base, under a strong glass, minute spiral striations 

 formed by the crinkling of the radiating costulae; light horn colored. 

 Whorls 4, regularly increasing, the last subangulate below the 

 periphery behind the outer lip for about \ turn, scarcely angulate 

 below, very sharply descending at the mouth; apex depressed, only 

 the last two whorls reaching the upper level of the shell. Aperture 

 very oblique, subhorizontal, rounded; lip simple, not thickened nor 

 sharpened, slightly reflected at the lower angle, extremities, 

 approaching, and joined by a slight callus in some specimens; aper- 

 tural lamellae five, two parietal and three (palatal) on the outer wall; 

 upper parietal lamella about central, the lower about midway between 

 this and the columellar junction and appearing about half the size 

 on external inspection, both showing a nearly triangular section, the 

 lower sides being nearly horizontal, the upper ascending; lower 

 palatal lamella beginning near the suture and extending nearly 



