294 BiUTISH ENTOMOSTRACA. 



Edwards afterwards adopted the genus, in his * History 

 of the Crustacea.' 



Anatomy, Sfc. — The body is of an ovoid shape, and of 

 a light horny colour and substance. The cephalo-thorax, 

 which includes the head and the first ring of the thorax, 

 is somewhat swollen, and of a roiuid figure in front, and 

 cut square at its posterior margin. It is smooth on its 

 dorsal surface, and does not appear divided into different 

 regions, as in Cecrops, The second and third segments 

 of the thorax are distinct, small, and narrow. The fourth 

 is considerably larger, and has attached to its upper edge 

 a large elytraform plate, which covers a great part of the 

 last segment. This segment is much the largest of all, 

 and in the female is dilated into the form of a broad and 

 rounded elytraform plate, which covers the abdomen 

 entirely. In the male it is not so large, and is simply 

 two-lobed. 



The abdomen, in the female, is large, oval, and deeply 

 notched posteriorly, and rounded at the sides into two 

 lobes ; w^hilst in the male it is short and narrow. The 

 caudal appendages are small, and of an oval shape, with 

 four short, stout setae or spines, springing from their pos- 

 terior edge. The antennae are small, composed of three 

 short articulations ; the mouth-apparatus is of moderate 

 size, and the structure of these parts and the foot-jaws 

 is the same as in Cecrops. 



The males are much smaller than the females. The 

 young, from the figm^e of Kroyer, appear to resemble a 

 good deal the form of the Cyclopidae. The cephalo- 

 thoracic portion is large, and quadrilateral in shape, and 

 there are five distinct segments to be seen in the body, 

 gradually diminishing in size as they descend, without 

 any appearance of the elytraform appendages. It appears 

 to have two large round eyes, situated in the front of the 

 carapace. The antennae and the feet are more largely 

 developed than in the adult. 



