146 TECTIBRANCHIATA.—BULLADZ. 
ginning to disappear, pale colours are displayed 
by the shell, and its texture is stony. Its form is 
more or less rolled upon itself, but without a salient 
or produced spire, and the mouth is usually ample 
and widely expanded. 
The animal is large, fleshy, and often slimy. 
The gills are concealed, the tentacles are so much 
shortened, widened, and separated, that their form 
is well-nigh obliterated, and they constitute a large 
square fleshy veil, beneath which are placed the 
eyes. ‘The stomach is complicated, and in some 
species there is a shelly gizzard, with a peculiar 
erinding apparatus of great strength, needful for 
the demolition of the shells of other species of 
Mollusca on which the bullade feed. They are 
very voracious, and sometimes swallow bivalves so 
large as quite to distort their own form, and render 
it almost unrecognisable. The shelly gizzard of 
Scaphander lignartus, a large species not uncommon 
on our coasts, was described by Gioeni, a Sicilian 
naturalist, as a new genus of multivalve shells, to 
which he gave his own name, calling it Goenza. 
He even went so far as to describe the habits of the 
pretended animal, which was actually received into 
the catalogues of science by some of the most 
eminent names in conchology, until at length the 
imposture was detected and exposed. 
‘The animals of this family generally inhabit 
deep water, that is to say, below the range of low 
tide. Occasionally, however, they stray within 
tide-marks. 
