MANUAL OF THE MOLLUSCA. 
Shell like Pileopsis, dextral as in Velletia, with a respiratory 
channel on the right side. 
‘Animal with the respiratory orifice on the edge of the mantle. 
Hyes sessile at the middle of the hinder part of the base of the 
tentacles, and are visible only from above; tentacles rather 
conical than angular; upper mandible conspicuous, slightly 
lobed; lingual ribbon broad, with 86 rows of teeth, 87 in a 
row (43.1.43); they have simple obtuse hooks as in Ancylus ; 
the central row only differs in being symmetrical; the laterals 
diminish gradually from the 14th to the 48rd, and a second 
cusp makes its appearance, and increases until the three near 
‘the margin are regularly bicuspid.” sentra, ) 
The habits of C. T’heobaldi are terrestrial. 
This genus is doubtfully distinct from Valenciennesia. 
Poryis, Bourguignat, 1860. 
Dedicated to M. Poey of Havanna. 
Type, P. Gundlachioides, Cuba. 
_ Shell, above like Gundlachia, below like Ancylus; apex pos- 
terior, fexiel somewhat compressed, very obtuse; aperture 
large, peristome simple. 
BRONDELIA, Bourguignat, 1860. 
The two species Ancylus Drouetianus, Bourguignat, and 
B. gibbosa, Bourg., are terrestrial Ancyli, living on humid 
rocks in the forest of Hdough, Boué (Algeria). 
ACROCHASMA, Reuss, 1860. 
Type, A. tricarinatum, Reuss, from the fresh-water limestones 
of Bohemia. 
Shell trilateral, pyramidal, rounded-below in its whole ampli- 
tude, with one posterior concave, and two lateral slightly con- 
yex planes, ending upwards in an acute reflected apex, beneath 
with a longitudinal aperture through the shell, which in its 
living state appears to have been covered with an epidermis. It 
may be considered as a fresh-water representative of the marine 
genus Fisswrella. 
CHOANOMPHALUS, Gerstfeldt, 1859. 
Etymology, choanos, a funnel 3 omphalos, an umbilicus. 
Type, C. Maacki, Lake Baikal. 
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