214 
REALIA §. 3. 
ovato-rotundatus, subtus convexus, ad perforationis depressio- 
nem arete rotundatus, nec angulatus. Apertura subvertiealis, 
ovato-piriformis, 2 / 5 longitudinis aequans, intus cornea. Perist. 
rectum, acutum, non labiatum; marginibus approximatis, lamina 
parietali adnata junctis, externo et basali regulariter arcuatis, 
eolumellari reflexiusculo , ad insertionem paulo protracto. — 
Diam. maj. 2 1 / 4 , min. 2, altit. 3 1 / 3 mill. — Rat. anfr. 3:1. — 
Rat. apert. 3:5.“ (M.) 
Hydrocena parvula Mouss. in Journ. Conch. XIII. 1865. p. 184; XXL 
1873. p. 108. 
Omphctlotropis parvula Pease in Journ. Conch. XVII. p. 155. 
Habitat in insula Upolu; ins. Ellice (Graffe). 
35 ? R. pygmaea (Hydrocena) Gassies. f 
„T. imperforata, conica, tenuis, brunneo-rufa, unicolor, 
nitida, translucida, minutissime striatula; anfr. 5 — 6 sensim 
accrescentes , subrotundati; sutura mediocris; anfr. ultimus 
ventrosus, non carinatus, vix 2 / 3 longitudinis aequans, umbilico 
obstructo; apertura ovato-rotundata, parum obliqua; columella 
fulva, nitida, vix callosa, non continua; peristoma subincras- 
satum, intus brunneo-nitidum. — Operculum? — Long. 2 J / 2 , 
diam. D/ 2 mill." (G.) 
Hydrocena pygmaea Gass, 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. f 
„T. perforata, ovato-conica, turbinata, translucida, solidula, 
subtilissime longitudinaliter striatula, flavidulo- vel rubello- 
cornea; spira conico-pyramidata, acutiuscula; anfractus 5 l / 2 
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 junctis, eolumellari 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). 
37. R. rubra (Hydrocena) Gassies. f 
„Testa perforata, ovato-conica, turbinata, translucida, so- 
lida, subtilissime transversim striatula, rubello-cornea ; spira 
