144 TANAIDJE. 



ISOPODA. TANAIDJ&. 



ABERRANTIA 



Genus APSEUDES. 



Apseudes. LEACH, in Brewster's Edinb. Encycl. vol. vii. p. 404, 1812. 

 EDWARDS, Hist, des Crust, t. iii. p. 138, 1830. LILLJEBORG, 

 Bidrag. kan om de inom Sverige och Norrige forek. Crust, af 

 Isop. Tanaid. fam. p. 8, 1864. 



Eupheus. Risso, Hist, des Crust, des Nice, p. 124, 1816. 



Rhcea. MILNE EDWARDS, Ann. Sci. Nat. xiii. p. 292, 1828. 



Generic character, Body elongated. Head and first segment 

 of the pereion confluent. Upper antennae longer than the lower, 

 with the first joint of peduncle long and robust, the flagellum 

 consisting of two elongated articulated filaments. First pair of 

 gnathopoda chelate ; second pair having the propodos trans- 

 versely dilated. Pleon terminated by a large segment bearing 

 two long and two short slender filaments. 



THE head and first segment of the body are confluent, 

 the former advanced in front into a point, forming a 

 small triangular rostrum, the latter having the sides 

 dilated and depressed. The eyes are large and borne on 

 movable footstalks. The upper antennae are robust, 

 the first joint especially being long and stout ; the 

 flagellum or terminal portion is multiarticulated, and 

 provided at its base with a slender secondary filamentous 

 appendage composed of numerous articuli ; the lower 

 antennas are shorter and more slender, furnished with 

 a small squamiform movable process, as in the Ma- 

 crourous stalk-eyed Crustacea, and terminate in an articu- 

 lated and gradually attenuated flagellum. The mandibles 

 are small, slightly truncate, denticulated at the ex- 

 tremity, and furnished with a three-jointed palpiform 

 appendage. The outer foot-jaws are confluent at the base, 

 and terminated by three flattened joints strongly ciliated. 



