64 MISILUS. ae 2 
Th yy » 
the order Trachelipoda, containing the genera Melania, Mela- 
nopsis and Pirena. ‘To which may be added Anculosa and 
Pasithzea? Fig. 313 to 317. 
MELANOIDES. Olivier. Mevanopsis, Fer. 
MELANOP'SIS. Fer. Fam. Melaniana, Lam. Entomostomata, 
Bl. Descr. Oval or oblong, fusiform; spire acute, sometimes 
elongated; aperture oblong or oval, pyriform with a distinct 
notch at the anterior extremity; columella tortuous, callous, 
thickened at the extremity near the spire; epidermis thick, 
horny, generally black. Obs. This description includes Pirena, 
Lam. The Melanopsides are known from the Melaniz by the 
notch in the aperture. Fig. 315, M. costata. 
ME’LAS. Montf. Menania, Auct. 
MELEAGRINA. Lam. Margarita, Leach. A genus composed 
of the Pearl Oyster, and similar species, separated from Avicula 
on account of the roundness of their general form, but re-united 
by Sowerby. For generic characters, see Avicula. Fig. 164, 
M. margaritifera. 
MELEA’GRIS. Montf. Turso Pica, Auct. and similar species. 
having the aperture oblique, the columella gliding imperceptibly 
into the outer-lip, and having an umbilicus. 
MELI’NA. Schum. Perna, Auct. 
ME’LO. Brod. (Melo, a melon.) Fam. Columellaria, Lam. Deser. 
Light, ventricose, oval, witha light, greenish brown epidermis ; 
spire short, papillary, regular, sometimes hidden by the last 
whorl; aperture large, nearly as longas the whole shell, emargi- 
nated anteriorly; outer-lip thin; columella slightly curved, 
with four or five laminar, oblique, prominent, plaits. Obs. The 
genus Melo has been separated from Voluta principally on ac- 
count of the largeness of the aperture, the lightness of the shell 
and the thinness of the outer-lip. Melo differs from Cymba in 
the regularity of the spiral apex, and in the greater rotundity of 
the shell. ‘The Melons are beautifully coloured, large shells, 
found inthe seas of the old world. The Melo Indicus has a 
certain resemblance toa Melon. Fig. 435, M. Asthiopicus. 
MELO'NIA, or Me tonitss, Bl. A genus of microscopic Fora- 
minifera. 
MERCENA‘RIA. Schum. Venus Mercenaria, Auct. The Money 
Shell, which passes current as cash, under the name of Wampum, 
among the North American Indians. 
MERE’TRIX. Lam. Original name for Cytherza, Lam. 
ME’ROE. Schum. Cytherza sulcata, scripta, hians, Auct. and 
similar species. Fig. 117, a. 
MESODES’MA. Desh. Erycina, Lam. & : 
MESOM’PHYX. Rafinesque. A genus proposed to be separated 
from Helix, Auct. 
MILIOLA. Lam. A genus of microscopic Foraminifera. 
MISILUS. Montf. A genus of microscopic Foraminifera. 
