214 REALIA $. 3. 
ovato-rotundatus, subtus convexus, ad perforationis depressio- 
nem arcte rotundatus, nec angulatus. Apertura subverticalis, 
ovato-piriformis, ?/, longitudinis aequans, intus cornea. Perist. 
rectum, acutum, non labiatum; marginibus approximatis, lamina 
parietali adnata junctis, externo et basali regulariter arcuatis, 
columellari reflexiuseulo, ad insertionem paulo protracto. — 
Diam. maj. 2!/, min. 2, alüt. 3!/, mill. — Rat. anfr, 3:1. — 
Rat. apert. 9:25.* (M.) 
Hydrocena parvula. Mouss. in Journ. Conch. XIII. 1865. p. 184; XXI. 
1873. p. 108. 
Omphalotropis parvula Pease in Journ. Conch. XVII. p. 155. 
Habitat in insula Upolu; ins. Ellice (Gráffe). 
as. ? R. pygmaea (Hydrocena) Gassies. 1 
.I. imperforata, conica, tenuis, brunneo-rufa, unicolor, 
nitida, translucida, minutissime striatula; anfr. b—6 sensim 
acerescentes, subrotundati; sutura mediocris; anfr. ultimus 
ventrosus, non carinatus, vix ?/; longitudinis aequans, umbilico 
obstructo; apertura ovato-rotundata, parum obliqua; columella 
fulva, nitida, vix eallosa, non continua; peristoma subincras- 
satum, intus brunneo-nitidum. — Opereulum? — Long. 2!/, 
diam. 1!/, mill* (G.) 
Hydrocena pygmaea G'ass. in Journ. Conch. XV. 1867. p. 63. 
Assiminea. pygmaea. Pease in Journ. Conch. XVII. 1869. p. 165. 
Habitat in insula Art Novae Caledoniae (Montrouzier). 
36. R. Crosseana (Hydrocena) Gassies. 1 
, T. perforata, ovato-conica, turbinata, translucida, solidula, 
subtilissime longitudinaliter. striatula, flavidulo- vel rubello- 
cornea; spira conico-pyramidata, acutiuseula; anfraetus 5!/, 
convexi, subscalares, sutura profunda separati, ultimus ventro- 
sus, basi circa perforationem profundam obtuse carinatus; 
spira mediocriter elongata; apertura rotunda; peristoma sim- 
plex, rectum, marginibus callo tenui junetis, columellari in- 
crassato, brevissime reflexiusculo. — Operculum? — Long. 3, 
diam. 2 mill  Apert. 1 mill. longa, 1 lata.* (G.) 
Hydrocena Crosseana. Gass. in Journ. Conch. XVII. 1869. p. 77. 
Habitat in insula Art Novae Caledoniae (Montrouzier). | 
»;. R. rubra (Hydrocena) Gassies. 1 
»lesta perforata, ovato-conica, turbinata, translucida, so- 
lida, subtilissime transversim striatula, rubello-cornea; spira 
