CHEMNITZIA. 433 
cylindrical and narrow, and on the march, as is the invariable 
practice in all the species, it is in advance of the anterior 
portion of the foot, which, ike the terminus of the rostrum, is 
truncate and without the auricular points at the angles; it is 
rather broad, and when extended reaches halfway on the 
antepenultimate volution, posteriorly becoming a little con- 
stricted, and having a very rounded termination. The tenta- 
cula are triangular, bevelled laterally, poimted, with the usual 
two minute flake-white lobes at the tips, which may be partly 
real, but principally simulations that depend on the will of the 
animal; the lateral membranes, which are not so extensive as 
in some species, coalesce and form a shallow veil; the eyes 
are very close together exactly at the imternal bases, not im- 
mersed, but a little elevated on minute prominences. We 
may remark, that in this tribe the membranes on both sides 
of each tentaculum simulate all kinds of shapes and foldings, 
which have been termed auriform or subtubular; these are 
deceptions, and due to the will of the animal, as on the march 
the tentacula are always carried in a regular, smooth, trian- 
gular, bevelled position. These changes from one form to 
another only occur when the animal is disquieted; they are 
then frequently and suddenly made, and the tentacles as 
quickly assume a natural form. The operculum is of a narrow, 
rather elongated, oval shape, carried on a simple lobe at some 
little distance from the posterior terminus of the foot; it 
has the usual, characteristic, right-angled, semi-cartilaginous, 
minute, notched apophysis and oblique striz of the tribe. 
The animal is not at all shy, progresses rapidly, and in- 
habits the coralline zone at Budleigh Salterton, where we 
have taken it in 12 fathoms water, more than once, alive. 
The animal has not before been described. 
Cu. ELEGANTISSIMA, Mont. 
Ch. elegantissima, Brit. Moll. ni. p. 242, pl. 93. f.1, 2; and iv. p. 275. 
Animal inhabiting a white, spiral, elongated, glabrous shell 
of 12-16 costated volutions; it is, except the eyes, hyaline- 
white throughout. The produced rostrum is deeply grooved 
m the middle on the upper surface, and imperforate at the 
2F 
