LITTORINIDA. 159 
3. Risella nana. 
Trochus nana, Lamarck, Hist. 1822, Australia ; = Bembictum pictum, Phil. 
Zeits. Mal., 1846, Van Dieman’s Land, fide Phil. = R. nana Quoy 
[not Lam.]. 
4 Tasmania; ex c. G. Nevill, Esq. 
4, Risella lutea. 
Trochus luteus, Quoy, Voy. Astrol, 1832, “ Port du Roi-George”’ ; =Trochus 
cicatrosus, Jonas, Phil. Abb. 1843, Port Western, 
The Rev. Tenison-Woods considers this species as a sexual 
variety of R. plana. 
30 Pt. Jackson and Moreton Bay; coll. G. Nevill, Esy. 
Sub-Genus PEASIELLA, nov. 
Type, Trochus tantillus, Gould. 
E. A. Smith in the Journal, Linnean Soc., XII, 1876, p. 552, 
describes the operculum of RB. tantilla as ‘“ truly appertaining ”’ 
to the Family Trochide, being concentric and multispiral, 
but that for other reasons he considers it should be located with 
the Genus Risella. 
A species from the Loyalty Islands has been described by 
Montrouzier, J. de C., 1879, as “ Hchinella gaidei, long. 33, 
diam. 43 mil.”; apparently this must be a close ally of the 
Andaman form. I have named this new group in honour of 
the late Harper Pease, Hsq.; it is easily distinguished by the 
perforate or umbilicate base, &c. 
5. Risella [Peasiella] tantillus. 
Trochus tantillus, Gould, P. Bost., S. III, 1849, Sandwich Islands. 
20 Sandwich Islands; coll. H. Pease, Esq., Dr. H. Dohrn, and Prof. 
W. Newcomb. 
var, parvula, 
Risella parvula, Dunker, Cat. Mus. Godef. IV, 1869, Samoa. 
1 Samoa; ex Mus. Godeffroy. 
