130 MOLLUSCA. 
CINGULA PETENINGENSIS. 
Testa minuta, sub-perforata, elongato-conica, tenuis, levis, cinereo-viri- 
dis: spira anfractibus sex convexis ; sutura profunda: apertura lu- 
nata, trientem longitudinis teste adequans, antrorsum sub-producta ; 
lahits posticé interruptis. 
SHELL minute, smooth, elongate-conical, thin, of a grass-green co- 
lour when fresh, becoming ashy-green when dry. Spire composed 
of six convex whorls, separated by a deep suture; the last whorl a 
little more than half the length of the shell. Aperture about one- 
third as long as the shell, semilunar, a little produced anteriorly, the 
lips interrupted by the penultimate whorl. The axis is slightly per- 
forate. 
Length one-third of an inch; breadth one-tenth of an inch. 
Found adhering to grass on the margin of Lagoa de Peteninga, 
about six miles from Rio de Janeiro, near the northern entrance of 
the harbour. The water is here quite saline, the sea breaking into 
the lake in storms. [. P. c.] 
The operculum is horny and sub-spiral. As it inhabits the vicinity 
of brackish water, I doubt not it must be grouped with Turbo minu- 
tus, Totten, and Lvttorina balthica, and not with Melania, as Mr. 
Couthouy conjectured. Several small shells of this character are 
figured by D’Orbigny, under the name of Paludestrina, but none 
of them accord with this species. 
Figures 152, 152 a, two views of the shell, enlarged; 152d, natural 
size. 
Metanopsis ZELANDICA (Gould). 
Testa solida, ovato-conica, nitida, olivacea, fusco-trifasciata: spira 
conica, brevis, acuta; anfractibus tribus, supernis planulatis et ad 
suturam confluentibus ; ultimo magno, posticée planulato, anticée ventri- 
coso: apertura elliptica, cwrulescens, rufo-fasciata, posticé in canalem 

