196 PLANORBIS. 
above and below planulate and having an um- 
bilicus in the centre; whorls five, subrotund, 
moderately increasing, separated by a deep 
suture; aperture oblique, roundly lunate. 
Diameter 8, alt. 2°6 mill. 
Texas (Cuba; Vera Cruz, Mexico.) 
I cannot detect any difference between Pl. 
Havanensis and Pl. Inebmanni, and therefore 
unite them. 
Mr. Binney has considered Pl. gracilentus, 
Gould, a synonym of Liebmanni, but the lat- 
ter is a higher and smaller species, inhabiting 
a different district. 
Subgenus PLANORBELLA, 4aid. 
10. PLANORBIS CAMPANULATUS, Say. 
Hald. Monog. p. 9, t. 1, figs. 7—11. 
(43) 
