Dr Johnston’s Contributions to the British Fauna. 219 
pable of extension. The mouth is naked, nearly terminal, placed under the 
first segment, which may properly be considered as the head of the animal, 
and which is marked on each side with a curved black line ; but no eyes are 
perceptible. The two next rings bear neither filaments nor papillae. From the 
anterior margin of the fourth, which becomes suddenly larger, arises on each 
side a bundle of filaments, generally more tortuous, and of a paler colour than 
the others, which arise from the sides of the following rings, down about one- 
fifth of the length of the animal, and a few remote filaments are dispersed 
irregularly on the rest of the body. The filaments take their rise from near 
the back, some from the back itself, are about twenty in number on each side, 
worm-like, tortuous or extended, unequal in length, the shortest being placed 
anteriorly, but the gradation is not regular. They consist of a large central 
vessel carrying red blood, surrounded by a white gelatinous transparent mem- 
brane, and are consequently of a fine red colour ; but this is liable to varia- 
tion ; for some, particularly the anterior fasciculi, are often quite white, and 
others, again, are occasionally spotted as from a partial stagnation of the blood 
in them. There are also two rows of papulous feet on each side, armed with 
a few short unequal bristles, and at least, in a great measure, retractile. The 
ventral surface is flattened, marked in the middle, from the deeper colour ap- 
parently of a large vessel or intestine which runs from one extremity to the 
other. Anus terminal. 
1. C.Juscescens. Body of a dark-brown colour. 
Hab. Sea-shore. Under stones in muddy places, common in the neigh- 
bourhood of Berwick. 
Des. Body, when extended, three inches long, thicker than a crow-quill, 
of a dirty brown colour on the back, stained from the internal viscera ; ventral 
surface of a yellowish-brown. 
2. C. flavescens. Body of a yellowish colour, much stained 
from the internal viscera. 
Hajb. Sea-shore. In muddy places with the preceding, and equally com- 
mon, Berwick. 
Des. This is of the same size as the preceding, from which it appears to 
be sufficiently distinct. It is of a yellow colour, much stained on the back 
from the dark internal viscera. One or two of the specimens we examined 
were mottled on the back with circular closely-set spots, so small as to require 
a magnifier to see them ; but this character does not appear to be uniform. 
The ventral surface is much of the same colour, but not marked, unless in the 
middle with a mesian line. 
2. LEACIA. 
Cl. CRUSTACEA. — Ord. Malacostraca. 
Leg. Edriophthalmia. 
Char. Antennae four ; the superior very short ; the inferior 
nearly as long as the body. Body linear, of nine segments ; 
