186 BRITISH ENTOMOSTRACA. 



seems to be ignorant of his discoveries, though the work 

 of Ramdohr preceded his by fifteen years. 



Gunner,* Strom, f Tilesius, J Viviani, &c. had all 

 noticed or described various species, previous to Jurine's 

 time, and several new species have been described since ; 

 but, subsequently to his history, no work has been exclu- 

 sively devoted to the Entomostraca. 



Mr. Templeton, however, has added several new species 

 belonging to this family, which he discovered within the 

 tropics, and Koch has described a good many in Germany, 

 while M. Milne Edwards has bestowed much pains in 

 elucidating their systematic arrangement. 



Lately Mr. Dana has added a great many species, dis- 

 covered by him during the American voyage of exploration 

 under Captain Wilkes, and has described them in the 

 ' Proceedings of the American Academy of Arts and 

 Sciences' for 1847 and 1849. 



Anatomy and Physiology, fyc. The body of the animal, 

 which is soft and gelatinous, is inclosed within a horny 

 shell, which covers it like a buckler, but opens interiorly 

 to give issue to the antenna), organs of the mouth, and 

 feet. In general the thorax and abdomen are pretty 

 easily to be distinguished from each other, and are com- 

 posed of about ten segments, the thorax usually having 

 four, and the abdomen six. In the upper or cephalo- 

 thoracic segment, which is usually much the largest of all, 

 we iii id the eye, the antenna?, mandibles, mouth, a pair 

 of foot-jaws, and one pair of feet. 



The eye is situate near the upper extremity of this first 

 M Lament, and in the centre. It is tolerably large, and is 

 Dingle, and in some, as in the /V/V//>/W//,v Castor, we can 

 perceive the muscles which move it, of which there are 

 M'\eral. The antenna- are four in number. The superior 



: * Skril'tcr sum udi del Kiuhriihaviiskc Sclskab., Drrl x, I/' 1 



t ll.i.l., Drrl ix, [765. 

 : \lrmoin > ilr I'A.Mil. Imjiri. deS N/iril. ilr IVtri >l)cliri:. V. 



. riiu-.|i||iiiciili;i Minis, A.T., " 



