Synopsis Fresh-Watkr Mollusca 



15 



Genus CARINIFEX W. G. Binney, 1863. 



Shell spiral, clextral, inflated, angular; spire terraced; whorls numerous, 

 visible above, last whorl very large, broad above, rapidly attenuated below, 

 visible above, last whorl very large, broad above, rapidly atten- 

 uated below, umbilicus funnel shaped ; aperture triangular, 

 broad above, narrow below; inner lip slightly thickened; outer 

 lip thin, acute, angular above, flexuose. 



Animal sinistral, resembling Planorhis, but with much 

 shorter tentacles; jaw single; radula simliar to that of Pom- 

 pholy.v. 



1 1 I 



II io 22 



9 ac^e^^c^e^ 



Fig. 40 

 Type: Plaiiorbis nczcbcrryi Fea, fig. 40. Radula and jaw, fig. 41. 



Family PHYSID.F:. 



Shell spiral, sinistral, thin, smooth or with microscopic transverse striae, 

 shining, spire more or less produced. 



Animal sinistral, having the pulmonary, genital and excretory orifices 

 on the left side; tentacles slender, cylindrical; foot narrow, pointed behind; 

 jaw single, arcuate, with a vertical fibrous accessory process on the superior 

 margin ; radula with the teeth arranged in oblique rows. Central tooth wide, 

 Ijase with projecting processes before and behind, multicuspid; laterals 

 obliquely bent, comb-like, multicuspid, with a peculiar process at their ex- 

 ternal angle. 



1. Shell elongate, slender, smooth, polished, inner edge of 



the mantle simple, not digitate, not extending beyond 



the shell Aplexa. 



2. Shell less elongated, body whorl usually inflated, smooth 



or with microscopic revolving striae ; inner edge of the 



mantle digitate or lobed, extending partly over the shell. .Pliysa. 



Genus PHYSA Draparnaud, 1801. 



Shell sinistral, oblong, thin, translucent, shining; spire acute, usually 

 short ; whorls convex ; aperture ovate, rounded below ; columella twisted, 

 lip thin, acute, sometimes thickened within. 



Animal as in the family, but with the inner margin of the mantle digitate 

 or lobed, and extending over the shell. 



