298 



lIANtJAL OF THE MOLLHSCA. 



ViQUESNELiA, Deahayes, 1857. 

 Shell internal, rudimentary, oval, suborbicular, slightly con- 

 cave below, and thickened at the edges ; summit sub-central. 



Fig. 12o. Testacella hahof aides, 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 lingual 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. 



Fifr. 1264 



During winter and dry weather the Testacella forms a sort 

 tn -..-^j^^^^?^,. ^^ cocoon in the ground by the exudation 



"'l^f^i M ' ' "" ^^ ^^^ mucus. If this cell is broken, tho 

 u^ animal may be seen completely shrouded 



/ 



f'A""'"^''fi* ^^ ^^^ ^^^^ opaque white mantle, which 

 >5^^^ rapidly contracts until it extends but a 



F.ig, 127. Testacella. 



little way beyond the margin of the shell. 

 Fig, 127 represents T. Maugei (lately 



* Back view of a lialf-grown individual ; side view of shell on the tail, and front 

 view of the head. From specimens communicated bj- Arthur Mackie, Escv, of Norwich. 



t Part of the lingual membrane of 7'. halLotoides, from a preparation by FisliCT 

 Cocken, Esq., of Botesdale. The dentition resembles that of lanthiiia. 



