96 AURICULIDA. 
TRALIA, Gray, 1840. Shell oval, smooth, spire moderate ; 
aperture narrow, linear, wider in front ; columellar lip with three 
oblique plications; outer lip sharp, sinuous posteriorly, inter- 
nally callous, with one or several strong revolving ribs. Foot 
not transversely divided, the posterior extremity attenuated, 
not bifid. West Indies. J. pusilla, Gmel. (cii, 81). Should, 
perhaps, be considered a distinct genus. 
prrA, H.‘and A. Adams, 1853. Shell oval, smooth; spire 
elevated; aperture linear; columellar lip usually with three 
anterior plications; outer lip with numerous revolving riblets, 
forming tooth-like terminations. MM. angiostoma, Desh. (cii, 82). 
TIFATA, H. and A. Adams, 1858. Shell oval or elliptical ; 
aperture narrow, contracted, curved; columella produced, with 
two lamellar plications; outer lip smooth or minutely dentate 
within, margin acute. WM. oliva, d’Orb. (cii, 83). 
stiantA, H. and A. Adams,1855. Shell decussate or granular ; 
columellar lip with transverse plaits; outer lip with a simple 
elevated transverse plication uponits inner face. M. graviferus, 
Mouss. (cii, 84). 
persa, H. and A. Adams, 1853. Shell oval, with longitudinal 
ribs and revolving strizw ; aperture rather large ; outer lip sharp, 
smooth within; columellar lip with transverse lamellar plications. 
M. costatus, Quoy (cii, 85). 
DETRACIA, Gray, 1840. Columellar wall not plicate, aperture 
very narrow. J cingulatus, Pfeiffer. West Indies. 
RuytipHorvs, Meek, 1873. 
Distr.—R. priscus, Meek (cii, 87). Cretaceous; Utah. 
Shell having the general aspect of Melampus, excepting that 
it has a series of small, oblique, short folds around the top of 
the somewhat shouldered whorls; while a slight curve in these 
little folds or costs indicates the presence of a faint sinus in 
the lip near the suture; it has two folds on the columella, while 
the outer lip is thin, and apparently entirely smooth within. 
OPpHICARDELUS, Beck, 1837. 
Distr.—1l1 sp. Australia, Polynesia. O. Australis, Quoy 
(cil, 86). 
Shell oval-oblong, umbilicated, smooth; spire elevated-conic ; 
aperture oval, elongated, angulated above; inner lip reflected, 
with two spiral plications, one of which surrounds the umbilicus ; 
outer lip thin, simple. 
AUTENOE, Guppy. 
Distr.—A. riparia, Guppy. Trinidad. 
Closely resembling Melampus and Laimodonta, differing 
chiefly from the former in its thin and horny shell, and from 
the latter in its short spire and longer aperture. 
