92 RISSOIDE. 
3 Roweiah and Aden [10, 4]; coll, J. B. Baxter and G. Nevill, Esqrs. 
var, 
1 Aden [83,33]; coll. G, Nevill, Esq. 
73, Rissoina orbignyi. 
Rissoina orbignyi, 4. Adams, P. Zool. 8. 1851, Luzon; fide Schw, long. 16°7, 
diam, 5 mil., as R. @ Orbignyi. . 
var. subspirata, nov. 
Long. 133, diam. 5, mil. Turriculate, like R. spirata, but 
aperture everted and canaliculate at columellar base, as in true 
Et. orbignyt. 
4, Aden; coll. G. Nevill, Esq. 
var. pachylabris, nov. 
Anfr. 8 to 9; long. 11}, diam. 4, mil., last whorl obsoletely 
spirally striate, last but one coarsely so, the others cancellated as 
in the normal form; a very broad callosity behind the thickened 
peristome ; aperture everted. 
2 Annesley Bay [type var.]; coll. W. T. Blanford, Esq. 
var. submarginata, nov. (? dist. sp.) 
Acuminate, pointed, subturriculate; nine whorls slightly con- 
vex, the embryonal two smooth, rounded, mammillate, the 
next four closely and evenly reticulate, almost granulose, the 
last three somewhat distantly spirally striate, with a narrow 
groove just below the suture, the last one relatively very 
short, with spiral striation less distinct; aperture everted,. 
columella short, abruptly bent back, behind the peristome a 
broad callosity. 
_, Long. 8}, diam. 3 mil. 
1 Andamans [type var.]; coll. G. Nevill, Esq. 
74, Rissoina percrassa. 
Rissoina percrassa, Nevill, Jour, Asiat. Soc. Bengal, 1874, pl. 1, fig. 13, 
Mauritius, long. 8, diam. 3 mil. : 
