424 PYRAMIDELLID. 
index fails when the species is sometimes with and sometimes 
without the denticle. 
This is a rare animal on the Devon coasts, but we have 
taken several at Exmouth in the coralline zone; it is by no 
means shy, marching with vivacity, and allowing a good exa- 
mination. 
Addendum. — The tentacular veil, or, in other words, the 
bases of the short, broad, leaf-like tentacula, are not entire, 
as stated above, but slightly emarginate in the centre, just 
dividing the leaves, and with a groove in continuation of the 
central indentation of the rostrum. 
The animal of this species is the southern variety mentioned 
by the learned authors of the ‘ British Mollusca,’ vol. i. 
p. 245, which is certainly the true C. rufa of Philippi and 
authors. Professor Forbes and Mr. Hanley, in their account 
of the “rufa,” have stated, that it is with some hesitation 
they have followed the suggestions of their friends: and well 
they might pause, as they have described an entirely distinct 
species, a northern one, the Chemnitzia fulvocincta of Thomp- 
son and Alder, for the true rufa, which we found thirty years 
ago at Exmouth, and of which we took five in 1850. The 
description of the animal in the ‘ British Mollusca’ refers to 
the C. fulvocincta, and appears to differ from ours of the true 
“rufa” in those slight specialties which might be expected 
in such congeneric creatures: it is really extraordinary how 
two species so totally different, as to the hard parts, should 
have been confounded. I will now state the distinguishing 
characters of each. 
The C. fulvocincta is well figured in the ‘ British Mollusca,’ 
under the title of C. rufa; it is more conical and tapers more 
rapidly than the true C. rufa; it has rarely more than eleven 
or twelve volutions, and sixteen to eighteen ribs, somewhat 
raised and sinuated ; each volution slopes from its base to the 
ascending suture, which is merely a fine line; it is very glossy, 
with a most conspicuous yellow or orange band spirally 
coasting the last five or six turns; the basal portion of the 
aperture is subrotund. 
The genuine C. rufa is generally larger, though it has some 
