Dr Johnston’s Contributions to the British Fauna. 221 
length to one half of the body, rounded and slightly tuberculated on the dor- 
sum, and with a tuberculated ridge on each side, separated by a smooth line ; 
ventral aspect smooth and membranous. The three segments which follow 
are short, equal, transverse, bearing each a pair of legs formed for creeping. 
These arise within a cup-shaped tubercle, are equal in length, of six joints, 
and armed with a claw. The joints are emarginate on the superior aspect of 
their tarsal ends, to allow of freer motion, — the femoral is long, the three 
tibial are short, and nearly equal, — the first tarsal is twice as long as the se- 
cond, which bears the claw. Caudal segment equal in length to the three 
preceding, composed of two inarticulate pieces, angulated, with a few small 
tubercles, and terminated by a strong triangular spinous process. On the 
ventral aspect are two linear oblong moveable plates, pointed behind, joining 
accurately, and enclosing three pairs of white processes. These consist of a 
stalk, which supports on its end two equal flattened joints, moveable, beauti- 
fully ciliated on their sides, and rounded apices, with long bristles, which are 
themselves minutely ciliated in a pectinate manner. Inhabits the sea, 
8. FUSUS, Lamarck. 
Cl. MOLLUSC A. — Ord. Trachelipodes. 
1. F. barvicensis. Shell ventricose, white, with longitudinal 
furbelowed ribs, continued obliquely across a flattened space at 
the sutures ; beak rather long, slightly ascending. 
Has. Sea-coast, near Berwick. 
Des. Shell white, half an inch long, and one-half as broad, with six whorls, 
divided by a flattened space, and longitudinally ribbed. There are thirteen 
ribs on the body-whorl, finely furbelowed, projecting a little at the suture, 
terminating on the beak, which is produced, and smooth towards its extremity. 
The indented appearance of the ribs is produced by obsolete transverse striae 
crossing them. The ribs do not terminate at the sutures, but are continued 
across by elevated striae. Aperture round, inclining to oval, with smooth lips. 
Qbs. The shells of Great Britain have been examined with so much care, 
that I give this species with some hesitation ; but at present, after an atten- 
tive examination of its characters with those already described, I believe it to 
be new. In shape it resembles the Murex bamfius , but in other characters it 
approaches nearly the M. gracilis , from which, however, it differs in being 
broader in proportion to its length, in having fewer whorls, in having no co- 
loured band, and in its ribs being indented and continuous ; whereas in the 
M. gracilis , they “ are separated by a flat space at the upper extremity of each 
whorl, and the transverse striae are there continued uninterruptedly in a spiral 
direction up the shell.” — Dillwyn’s Descriptive Catalogue , p. 742. In our shell 
there is no appearance of spiral striae ; and the elevated striae, which cross the 
flattened space, are to be considered as the continuation of the ribs. 
VOL. XIII. NO. 26. OCTOBER 1825. 
Q, 
