104 Dr. Suaw’s Defcription of 
tranfparent, and the general colour of the males is a very light 
brown, with a tinge of blueifh green, particularly on the head and 
legs. The females have lefs of the blueith tinge, and incline more to 
brown, except on the fpine of the back, which is of a deep dull 
blue, and which part in the males is of a deeper brown than the reft 
of the body. The head of the male is armed with two fangs of a 
very {trong appearance, and which end in two long hooks bending 
inwards; and between the fangs lies a very curious apparatus, which 
will be more particularly defcribed hereafter. The eyes are very 
protuberant, and, as it were, furnifhed with a ftalk, as in the reft of - 
the genus Cancer. The female is deftitute of the two Jong fangs 
which are fo confpicuous in the male, and, inftead of them, is only 
furnifhed with a ftrong, thick, fhort pair of forceps: but what 
principally and immediately diftinguifhes the female, is a large, oval, 
fharp-pointed bag of ova, which is fituated underneath the lower 
part of the body where the tail commences. It is remarkable that 
the fmaller fized females are frequently furnifhed with this bag of 
ova, as well as the larger ones. The tail, which is perfectly alike 
in both fexes, is of a red colour, more or lefs deep, from the middle 
to the very end, which is forked into two very {harp points. Thefe 
creatures fhould feem by their appearance to be of a predaceous 
nature, and I have no doubt that they really are fo; the ftruéture 
of their fangs feeming to be particularly adapted to the purpofe of 
feizing their prey: yet I never obferved thofe which I kept, to attack 
any of the animalcules which were in the fame water: on the con- 
trary, the Monoculus conchaceus very frequently affaults them, and 
adheres with fuch force to their tails, or legs, as fometimes to tear off 
a partin theftruggle. The C. ftagnalis delights much in funfhine, 
during which it appears near the furface of the water, fwimming on 
its back, and moving in various directions by the fucceffive undula- 
tions of its numerous fin-like legs, and moving its tail in the manner 
of 
