22 BRITISH ENTOMOSTRACA. 



at its extremity ; the second pair consisting of two portions 

 also, the internal of which is a short oval plate, ciliated 

 at its edges ; and the external longer, cylindrical, and 

 surmounted with a styliforin appendage. 



The body of the animal, consisting of the thorax and 

 abdomen, is of a nearly cylindrical shape, and is composed 

 of thirty articulations, which are joined to each other by 

 means of a membrane that permits a considerable degree 

 of motion. They diminish gradually in size as they reach 

 the posterior extremity, which projects for some distance 

 beyond the carapace, and are studded all over with short, 

 stout, hooked spines. 



The feet are very numerous, amounting to about sixty 

 pairs, and extend from the mouth downwards, lying 

 along the edge of the alimentary canal. The first pair 

 (t. I, f. d} are very long compared with the others, 

 are situated immediately behind the mouth, and are 

 ramiform. They are composed of a basilar portion, and 

 several appendages. The basilar part is divided into 

 three joints : the anterior joint gives off two very long, 

 cylindrical, moveable appendages, which consist of nu- 

 merous small articulations (the one having about sixty 

 and the other about fifty), and a short, flat body ciliated 

 on its edges, which Schoeffer describes as a claw-like pro- 

 duction. The middle joint gives off another numerously 

 articulated cylindrical appendage, formed exactly like the 

 other two, but shorter (having only about thirty articula- 

 tions), and, like them, possessing a great extent of motion ; 

 while the posterior joint gives off a fourth, somewhat simi- 

 lar, but much shorter (having only six articulations), and 

 apparently not possessed of any motion. At the extre- 

 mity of this joint are several ciliated bodies, which Schccffer 

 calls false teeth* (one being round and possessing very 

 short seta3, the other oval and having about thirty long- 

 ones); and underneath we see attached to the middle joint 

 a branchial plate, of a triangular form, with strongly 



* The figure I have .i;ivcn of (his pair of feet, being taken from the. organ 

 in ait u, these parts arc not exhibited. 



