CAMPECOPEA. 433 



I SOP ODA . 



NORMAL1A. 



Genus CAMPECOPEA. . (Leach.) 



Generic character. Oval and very convex ; sixth segment of 

 body entire, or armed with a single long tooth in the middle 

 of its hind margin ; articulated ramus of the uropoda forming 

 a long exserted curved plate : interior division obsolete, or very 

 minute. 



THE species of this genus are the smallest in the pre- 

 sent family. They have the body very much arched, and 

 capable of doubling itself closely up, but not into a perfect 

 ball. The sixth segment is larger than the seventh (and 

 in some individuals, which we regard as males, it is very 

 much enlarged), and produced in the middle of its 

 posterior margin into a long tooth, which extends back- 

 wards over the tail, but varying in length in individuals 

 according, probably, to the period of their growth. This 

 remarkable tooth, not having been represented by 

 Montagu, has been overlooked in the descriptions of the 

 genus and its species by Desmarest and other later 

 writers, although originally mentioned by Leach in the 

 " Dictionnaire des Sciences Naturelles." The seventh 

 segment of the body is very short, as is also the basal 

 division of the tail, whereas the terminal division of the 

 latter is of large size, rounded behind, entire, and armed 

 at each side with the greatly elongated, curved, lateral 

 appendages, the outer division of which is setose, and 

 the inner appears to be obsolete, or very minute. The 

 foot-jaws have the intermediate joints produced into 

 rounded lobes at the inner apical angles. The antennas 

 are cylindrical, with the basal joints thickened. 



VOL. II. F F 



