— 42 — 



part of the globule bent towards tlie anterior part, and 

 took ou aceelerated and rotary moticn inside the 

 Ou the 30th, some of them separated from the 

 gelatinous mass, which was rednced to a very thin 

 meiubrane, and floated freely on the surface of the 

 water, showing distinctly the nncler.s of the shell, the 

 white body of the aniiual, with its two teutacles, and two 

 very dark eyes. 



X. Familia PERISTOMACEA, Lamk. 



Genus Paludina, Lamk. 



P. thermalis, L. In aqueducts. 

 P. acuta ?, * Undetermined. 



Genus Rissoa, Freminville. 



R. costata, Desm. 



R. ventricosa ? , Desm. * 



R. vioiacea, Desm. 



R. exigua, Michaud. 



R. auriscalpiurn, L. 



R. monodonta, Biv. 



P. calathiscus, Laskey. 



R. montagui, Peyr. 



R. radiata, Phil. * 



R. fulva, Michaud; syn. R. rubra, Adams. 



R. bruguierii, Peyr. ; syn. R. conifera, Moutagu. 



R. cos3urae, Calcara * Giornale Lctterario per la Sicilia^ 



Ko. 226. Found in sandy places at St. Julian's. 

 R. phillippi, Aradi 

 R. coroii.it a ? , an Scalavia ? * 

 R. fasciata, •{• Nobis. * Found at St. George's Bay and at the 



Salins. 



t Testa minuta, microscopica, ovato-conica, apice subobtu- 

 so, pellucida, lsevi, lbida, fulvo-fasciata, anfractibus 4 sub- 



