SPARTEBRANCHIA. 205 
fleshy fibres, and, as I have mentioned above, passes through 
an opening in the right tentacle. The testicle occupies that 
space of the spiral portion which contains the matrix and ovary 
in the female. 
In both sexes there is a projecting fleshy line below the right 
tentacle, which passes under it to the bottom of the branchial 
cavity, is again continued and terminates in an aperture at the 
bottom of the matrix. 
Genus 94. VALVATA. 
Valvata, Miiller, Draparnaud, Cuvier. 
Testa spira depressa, infra apertissime umbilicata. 
Animal : os tubulosum, superné quasiarticulatum. Tenta- 
cula setacea, apice obtusa, superné ad basin oculigera. Bran- 
chie plumosze, retractiles. Pes antice bilobatus ; lobi acumi- 
nati. Processus carneus ad corporis dextrum setaceus, ad 
apicem obtusus, tentaculiformis. 
Shell with depressed spire, beneath very widely umbilicated. 
Animal. Mouth tubulose, upper aspect as if articulated. 
Tentacles setaceous, their extremities obtuse, bearing the eyes 
on the upper aspect of their bases. Branchize plumose, retrac- 
tile. Foot anteriorly bilobate, lobes acuminate. A fleshy pro- 
cess arises from the right side of the body, of a setaceous form, 
with an obtuse extremity resembling a tentacle. 
1. VaALvATA MULLERI. 
V. testa spira subelevata; anfractibus quatuor, planatis, trans- 
versim striatis ; apertura subreflexa ; umbilico lato. 
Valvata cristata, Mill. Verm. Hist. 1. 198; Cuv. Reg. Anim. 
rege a 
Helix cristatus, Mont. Test. Brit. u. 460. vig. 1. f. 7, 8. 
Turbo cristatus, M. & R. Trans. Linn. Soc. viii. 169 ; Dill. 
Desc. Cat. 883 ; Turt. Conch. Dict. 227. 
Valvata Planorbis, Drap. Hist. des Moll. 41. t. i. f. 34, 35. 
Planorbis cristatus, Flem. Edinb. Encycl. vii. 69. 
Habitat in paludibus vulgaris. Diam. ;% unc. 
