ONCHIDIUM. 
51 
part of the groove between the mantle and the 
foot ; foot narrowed ; shell none. 
On rocks near the sea covered with the tides, 
1. Onchidium. 
Animal oblong ; mantle completely covering the 
back, convex, coriaceous, tuberculated ; eyes 
two, at the end of cylindrical retractile pe- 
duncles ; tentacles none, or In the form of 
rounded oral lobes or a buccal veil; jaws none, 
tongue denticulated ; orifice of reproductive 
organs widely separated ; pulmonary cavity be- 
hind the heart, with the aperture posterior, 
between mantle and foot. 
11 . 1. Onchidium celticum , — Oblong mantle thick, 
coriaceous, rather shining, covered with short 
thick rounded tubercles, surrounded with smaller 
ones ; foot oblong. 
Onchidium celticum. Cuvier (?) ; Couch ; Forbes and Hanley^ 
iv. 3. t. FFF. f. 6. 
Inhab. Cornwall, on rock at West Comb in Sand- 
level Bay {J. CoucJi). 
The edge of the mantle considerably exceeds the 
foot; the under side of this edge minutely granulated; 
foot pale yellowish. 
J aws none ; tongue broad, and furnished with 
upwards of seventy transverse rows of blunt slightly 
curved teeth, each row containing 108 teeth, and 
divided by a minute central tooth of a triangular 
form bearing a single blunt spine. The reproductive 
organs are in the same individual. The male organ is 
