ANTHURA. 157 



terior of which are soldered together ; the fifth is a 

 small segment with the hind margin raised and notched 

 in the middle, and which supports the latero-caudal 

 plates ; and the sixth forms the large terminal central 

 plate of the tail. 



The family comprises three genera, of which the two 

 following are British. 



Genus ANTHURA. (Leach.) 



The body is very slender, elongated, and somewhat 

 triquetrous, having the head and segments of the body 

 quite distinct from each other; but the four anterior 



z 



SHAPE OF BODY. 



segments of the tail are confluent, and so closely attached 

 together, that, in fresh specimens, or in those preserved 

 in spirits, the articulations are not recognizable; the 

 penultimate segment of the tail is short, having on each 

 side a pair of scale-like appendages, representing the 

 terminal pair of tail-legs. 



The pleopoda consist of, at least, four pairs of 

 oval plates, strongly ciliated, on each side of the ventral 

 surface of the basal segments of the tail. They are 

 of nearly equal size, and arranged so as to lie longi- 



