822 RISSOIID^-JEPFREYSIIDiE. 



Combines the epidermis, and to a great extent the animal of" Hy- 

 drobia, witli the peristome of Rissoia and tlie operculum of JefFrey- 

 sia. 



Genus IKAVADIA, Blanford. 1867. 



Rissoiforni, the apex often obtuse, whorls spirally ribbed and 

 covered with an epidermis ; aperture ovate, margins continuous, 

 anteriorly slightly effuse, outer lip with an external varix. Oper- 

 culum and animal unknown. 



Brackish water. India. I. ornata, Blanford. 



Probably closely related to Fairbankia. 



Genus FI:NELLA, A. Adams. 1871. 



Shell turriculate, subulate, or pupoid, whorls cancellated ; aper- 

 ture oval in front, peristome interrupted, lip sharp, thickened or 

 varicose. F. PuroiDKS, A. Ad. Japan. 



(Some authors place Fenella in Pyrainidellida>. 



Genus PUTILLA, A. Ad. 1867. 



Shell turbinated-conic, solid, smooth, rimate ; aperture suborbic- 

 ular, lip thickened, subeffuse in front, scarcely expanded. Relation- 

 ships obscure. P. lucida, A. Adams. Japan. 



(knius SKENE LL A, Pfefter, 1886. 



Sliell depressed globose, compressed around the umbilicus; peris- 

 tome continuous, the inner lip straight, oblique ; operculum j^aiici- 

 spiral, with a pi'ojecting lamina, arising from the nucleus. 



S. (TEOR(4rANA, Pfeffer. 

 South Georffia. 



F A MIL Y JEI 1 11 E 1 \SIID.E. 



Proboscis bilobed in front, forming two shar}), narrow, ciliated 

 appendages as long as the tentacles, which are equally ciliated ; 

 eyes sessile at the base of the tentacles; foot lanceolate, flaws 

 scaly (PI. r)4, fig. 2). Radula variable, shoit, the central tooth 

 small, with slightly reilected margin, lateral tooth arcuate, some- 

 times denticulate, sometimes unarmed, marginal teeth absent or 

 present (PI. 54, fig. 1 ). 



Shell small, thin, transi>ar('nt, with oval aperture. Operculum 

 inil)ricated, concentric, with marginal inicleus, th(> iiniei- fnce with 

 a transverse carina (PI. 54, figs. 96, l)7j. 



