RISS0IDJ3. 93 



1 Maurifcms [type] ; coll. G, Nevill, Esq. 



One of the most remarkable species of tlie Genus. 



Section G. — Zebina, H. and A. Ada?ns» 



Gen. Moll. I, p. 328, 1855, type E. coronata, Secluz ; = Group VI, 

 Schtvartz, I. c, pa^e 39. 



75. Rissoina tridentata. 



Eissoa tridentata, Michaud, Descr. Coq. nouv, 1832 ; fide Schwartz, long. 

 8, diam. 4 mil., from Med Sea, Philippines, Mauritius and Sandwich I.; 

 Suez, fide M' Andrew ; fide Fease = R. crassilahrum, Garrett, 1857 ; 

 from Tahiti, fide Grceffe. 



2 N. Caledonia; ex. c. P. Bouvier, Esq. 



1 Koweiah, Ked Sea ; coll. J. B. Baxter, Esq. 

 12 Mauritius [9-jL, 5], Andanians and Ceylon ; coll. G. Nevill, Esq. 

 4 Sandwich Islands; coll. H. Pease, Esq. [65, 85]. 



76. Rissoina coronata. 



Rissoina coronata, Secluz, ms., Schtvartz, Denies. K, Ak. Wissen. Wien, 

 XlX, 1860, Mauritius, long. 53, diam. 2'3 mil. ,-? = £. bidentata, Phil., 

 and var. from lJpolu,fide Schmeliz, I. c. V. 



1 Mauritius ; coll. G. Nevill, Esq. 



It. affinis, Garrett, P. Ac. Phil. 1873, Viti Is., long. 5 mil,, 

 must be close to this species ? 



77. Rissoina bidentata. 



Bissoa bidentata, Phillipi, Wiegm. Arch. 1845, p. 64, Friendly Isl., 

 long, f, diam. 1^ ; fide Schtvartz, long. 6'5, diam. 2'S mil., Mauritius 

 and Friendly Islands. 



3 Mauritius [5|, 2^] ; coll. G. Nevill, Esq. 



Besides the dentition of the aperture, the differences in the 

 shape of the spire, whorls, &c., easily and certainly distinguish 

 it from E. tridtntata. 



