principally marine, found on the South Coast of Devonshire. 5 
and marked with two streaks of black, one on each side the eye, 
probably the reflection of a pupil. 
This is another species of Cancer that very nearly approaches 
the genus Oniscus, and is readily distinguished by the larva-like 
appearance of its head. It is not uncommonly taken with the 
last. ; 
CANCER GAMMARUS MONOCULOIDES. 
Tas. II. Fig. 3. 
Body slender, compressed, with ten smooth joints of a pale 
colour, the seven first connected with a broad plate on each side 
of an oval shape, which appears capable of closing, and receiving 
all its external members, such as the legs, antennæ, and probably 
the caudal fins: no visible arms, but it has several pairs of legs 
armed with slightly hooked subulate claws: antenne four, the 
upper pair rather the longest, and about half the length of the 
body: eyes very minute: caudal fins three pairs, subulate. 
Length one eighth of an inch. Not common. 
This species seems to connect the Cancer with the Monoculus, but 
is more allied to the former in the conformation of its members. 
CANCER GAMMARUS OBTUSA TUS. 
Tas. II. Fig. 7. 
Body slender, compressed, with eleven smooth joints, indepen- 
nues of the head, and of a pale brown colour, usually mottled with 
rufous-brown when alive, especially about the legs: antenne 
four, the superior pair nearly as long as the body, the others 
somewhat shorter : eyes very small, and of a pale colour: arms 
four, the anterior pair very small; the others are furnished with. 
large hands differing a little in different specimens ; but the claw, 
which is a little hooked, is always obtuse at the end, and some- 
times 
