120 
BRITISH ENTOMOSTRACA. 
a point near the root of the antennae, and almost upon the 
extremity of this point is situate the black spot in front of 
the eye. A short distance from this the body has an in- 
dentation, in which, or rather on its edge, is situate the 
eye, already described. It then takes a round turn, the 
edge of which is more or less crenated, and from it the 
muscles attaching the body to the shell arise. It now 
turns inwards for a short distance, and then bulges out- 
wards again towards the posterior edge, terminating by a 
joint in the abdomen/' The space left where the body 
turns* inwards, between it and the shell, is the matrix, 
or place where the animal deposits its ova, and where the 
young remain till ready to be extruded ; and immediately 
above this is situate the heart. 
The abdomen (t. XV, f. 1^) in all the species I have 
examined is connected to the body by an articulated joint, 
differing in this very particularly from the Daphniadae. 
At this joint we see two setae arise, which in some species, 
as in the JEurycercus lamellatus , are beautifully plumose, 
and of considerable length. The abdomen is then pro- 
jected upwards, being always within the shell when the 
animal is at rest. It terminates in two or more hooks, 
the use of which seems to be to assist in cleaning the in- 
terior of the shell, as the abdomen is flexible, and can be 
extended at pleasure to a considerable extent beyond the 
carapace. In one or two species it is remarkably long, as 
in the Camptocercus macrourus, and is extremely flexible, 
the motion of this organ being evidently of great use to 
the animal in assisting and regulating its movements. A 
little beyond this joint is placed the anus, or termination 
of the alimentary canal. 
The feet are five pairs in number (t. XV, f. 1 e-i) ; the 
first pair are the largest, and consist each of a fleshy sort of 
body, bent a little, strongly ciliated on its upper edge, and 
furnished at its extremity with five long and strong setae, 
which in general project a little beyond the edge of the 
* The body, as above described, is particularly well seen in the Acroperus 
harpce. 
