EISSOID.E. 

 3 Roweiah and Aden [10, 4] ; coll. J. B. Baxter and G. Nevill, Esqrs. 



var. 

 1 Aden [8--, 3*] ; coll. G. Nevill, Esq. 



73. Rissoina orbignyi. 



Rissoina orbignyi, A. Adams, P. Zool. S. 1851, Luzon ; fide Schiv. long. 16'7, 

 diam. 5 mil., as It. d' Orbignyi. 



var. subspirata, nov. 



Long. 13J, diam. 5^ mil. Turriculate, like H. spirata, but 

 aperture everted and canaliculate at cokimellar base, as in true 

 H. orbignyi. 



4 Aden ; coll. G. Nevill, Esq. 



var. pachylabris, nov. 



Anfr. 8 to 9 ; long. 11J, diam. 4^ mil., l as t 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. 8J, diam. 3 mil. 



1 Andauians [type var.] ; coll. G. Nevill, Esq. 



74. Rissoina percrassa. 



Rissoina percrassa, Nevill, Jour, Asiat. Soc. Bengal, 1874, pi. 1, fig. 13, 

 Mauritius, long. 8, diam. 3 mil. 



