from Central and South America. 497 



ovei' the upward extension of the last wliorl near the aperture, 

 so noticealDle in the present species, is totally lacking ia 

 P. guadeloupensis. 



PJanorbis Boiicardiana, sp. n. (Fig. 17.) 



Shell depressed, subcarinace, whitish grey; whorls 4, 

 sculptured with fine oblique strise ; spire concave ; umbilicus 

 wide, very concave, especially in the centre; peristome 

 simple, very oblique, broadly lunate. 



Alt. 2, diam. raaj. 7 mm. 



Aperture : alt. 2, diam. 1'25 mm. 



Hub. Mexico. 



Planorbis meridaensis^ sp. n. (Fig. 18.) 



Shell depressed, suborbicular, dull brown ; whorls 3^, 

 marked with oblique arcuate lines of growth; right side 

 deeply excavated, especially in the middle ; lett side some- 

 what concave ; peristome acute, a callus on the parietal 

 whorl joining the two margins of the peristome ; aperture 

 obliquely lunate. 



Alt. 3, diam, maj. 8 mm. 



Aperture : alt. 3, diam. 1*5 mm. 



Hab. Merida, Venezuela. 



Phijsa balteata^ sp. n. (Fig. 19.) 



Shell fusiform, pale yellowish horn-colour, transversely 

 marked with oblique, buff-coloured bands; whorls 6, the last 

 somewhat inflated and sculptured with very tine transverse 

 strige ; sutures rather deeply impressed; edge of peristome 

 acute^ a thickening appearing just within the shell ; columella 

 straight, white, descending somewhat obliquely, a very thin 

 callus joining it with tlie lip above; aperture elongateiy, 

 inversely auriform. 



Alt. 12*5, diam. maj. 6'75 ram. 



Aperture : alt. 8, diam. 3*5 mm. 



Hab. Oaxaca, Mexico. 



Physa cornea, sp. n. (Fig. 20.) 



Shell fusiform, thin, polished, transversely striated with 

 irregular and somewhat distant lines of growth and spirally 

 sculptured with very fine wavy striae; whorls 5^; sutures 

 impressed; peristome acute; columella twisted, descending 



