334 CLASS CRUSTACEA. 



a profounder study than has been bestowed upon it by 

 Milller, our only authority on the subject. According to him, 



Cytherea, Mull. Cytherina, Lam., 



Would have eight simple feet, finishing in a point, though it 

 is probable that there are but six ; two antennae, equally sim- 

 ple, setaceous, composed of five or six articulations, with 

 some scattered hairs. 



They are found in the salt waters and the brackish waters 

 of the sea-shores, among the sea- weed and confervee. 



If these entomostraca are exclusively marine, it is not sur- 

 prising that Jurine and other observers, whose researches, in 

 consequence of the places of their residence, could extend 

 only to the entomostraca of the fresh water, should not have 

 spoken of the Cy therese. 



Cypris, Mull., 



Have but six feet, though M. Ramdohr says four, and M. 

 Jurine eight. The first considered the last two as appen- 

 dages of the male sex ; and the second took the palpi of the 

 mandibles, and the branchial plate of each upper jaw, for so 

 many feet. Nor did the latter reckon in this number, those 

 which the former presumed to be sexual organs. He regards 

 them as filaments of five articulations, issuing laterally from 

 the pouch of the matrix, and the use of which he is ignorant. 



The two antennae are terminated in the manner of a fasci- 

 culus of setae, like a brush. 



The testa, or shell, forms an ovaliform body, arched and 

 gibbous on the back, or on the side of the hinge, almost 

 straight, and a little emarginated and reniform, on the oppo- 

 site side. In front of the hinge, in the medial line, the eye 

 forms a thick blackish and round point. The antennae, in- 

 serted immediately underneath, are shorter than the body, 



