298 MANUAL OF THE MOLLUSCA. 
VIQUESNELIA, Deshayes, 1857. 
Shell internal, rudimentary, oval, suborbicular, siightly con 
cave below, and thickened at the edges; summit sub-central. 
Fig. 125. Testacella haliotoides, Fer.* 
TESTACELLA, Cuvier. 
Shell small, ear-shaped ; situated on the posterior extremity 
of the body. 
Animal, slug-like, elongated and tapering towards the head ; 
back with two principal lateral furrows, from which numerous 
vein-like grooves ramify; mantle not larger than the shell; 
respiratory orifice on the right side, beneath sub-spiral apex of 
the shell; reproductive orifice behind the right tentacle. The 
Testacella is subterranean in its habits, feeding on earth-worms, 
and visiting the surface only at night. Its hngual membrane 
is very large and wide, with about 50 rows of 20.20 teeth, 
which diminish rapidly in size towards the centre; each tooth 
is slender, barbed at the point, and slightly thickened at the 
base, and furnished with a projection on the middle of the 
posterior side. 
wr Nyall” he Yi f EEO - 
NA 
\ f 
Fig. 126.7 
During winter and dry weather the Testacella forms a sort 
of cocoon in the ground by the exudation 
. of its mucus. If this cell is broken, tho 
SS animal may be seen completely shrouded 
in its thin opaque white mantle, which 
rapidly contracts until it extends but a 
little way beyond the margin of the shell. 
Fig, 127 represents JZ. Maugei (lately 
* Back view of a half-grown individual; side view of shell on the tail, and front 
view of the head. From specimens communicated by Arthur Mackie, Esq, of Norwich, 
t Part of the lingual membrane of TZ. haliotoides, from a preparation by Fisher 
Cocken, Esq., of Botesdale. The dentition resembles that of /anthina. 
Fig. 127. Testacella. 
