158 UTTORINID^. 



Very probably belongs to tlie Litioj)ince, near Alaha, Dlala, 

 &c. 



1. Plesiotrochus, n. sp. 



An interesting form of this very distinct new Genus wliicb 

 I have for several years intended to describe. The whorls are 

 characteristically concave. 



10 Mauritius ; coll. G. Nevill, Esq. 



1 Audamaus; coll. Dr. F. Stoliczka. 



2. Plesiotrochus [?] n. sp. 



2 Persian Gulf ; coll. W. T. Blanford, Esq. 



Sub-family FOSSABIN^, Stoliczka. 



Genus RISELLA, Graij. 



Syn. Brit. Mus. 1S40, type Trochus melanostoma, Om. ; = Bemhicium, 

 Fhilippi, Zeits. Malac. Ill, 1843. 



1. Kisella plana. 



Trochus plana, Quoy, Voy. Astrol. 1832, " Port Western," Bass's Strait ; 

 =:Littorina australis. Gray, Beechey's Voy. 1839; var,=S. yrisea, 

 Fhil., Zeits. Mai. 1851, Sab. ? 



7 Australia ; ex c. Asiat. Soc, Bengal [coll. Strange]. 

 4 South Australia ; ex c. British Museum and Miss Pelly. 



Agree with figure, in Concb. Cab. II, of B. grisea, Phil. 



1 Port Mackay ; ex Mus. GodefProy [as " var. B., Crosse "]. 

 30 Port Jackson ; coll. Dr. J. C. Cox and G. Nevill, Esq. 



2. Risella imbrioata. 



Littorina irabricata, Gray, Beechey's Voy., 1839 ^sine Hab.^ ; = Risella 

 kielmannseggi, Frauenfeld, 1866, N. Zealand. 



I Australia i ex c. G. Nevill, Esq. 



