AMPULLARlNiE. 



S39 



SuB-FAM.? THALLTCERA. 



Thallicera Qwoy. Shell globose; spire depressed; 

 outer lip thin_, with a sinus above ; inner lip thick- 

 enedj with a prominent plait near the base. 

 T. avellana. (Jig. 34. p. 196.) Chem. 188. f. 1919-20. 



SuB-FAM. AMPULLARIN^. 



Animal with a respiratory siphon ; shell globular or 

 turbinate. 



Valvata Drap* Shell turbinate^ sometimes nearly dis- 

 coid ; spire very short ; the whorls convex ; aperture 

 circular ; operculum spiral ; umbilicus pervious. 

 V. piscinalis. Sow. Man. f. 322. 



Ampullaria Lam. Shell glo- 

 bose^ rarely discoid, turbinate ; 

 spire very short ; aperture ob- 

 long, pointed above, rounded 

 below. 



Ampullaria Lam. Outer lip thin ; 

 operculum horny. 



fasciata Lam. (fig. 101. a.) 



Pachylabra.^ Outer lip thick- 

 ened ; operculum shelly, 

 globosa ^M.'. Zool. 111. 1. pi. 119. 



Lanite.9 Montf. Shell reversed ; 



the body- whorl ventricose only in the middle ; outer 

 lip generally thin. 



L. Guinaica. Sow. Man. f. 319. 



Ceratodes Guild. Shell discoid ; body-whorl higher 

 than the spiral whorls ; outer lip thin ; operculum 

 horny. 



C. Cornu-Arietis. Sow. Man. f. 320. 



Paludina. Spiral ; spire equal, or longer than the 

 aperture ; lips thin. 



* Affinities uncertain. 



t Pachystoma Guild., already used in Iclitlivology. 



z 2 



