144 TANAIDA. 
ISOPODA, TANAIDA. 
ABERRANTIA 
Genus—APSEUDES. 
Apseudes. Leacu, in Brewster's Edinb. Encycl. vol. vii. p. 404, 1812. 
Epwarps, Hist. des Crust. t. iii. p. 138, 1830. LitisEBore, 
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. 
Rhea. Minne Epwarps, Ann. Sci. Nat. xiii. p. 292, 1828. 
Generic character —Body elongated. Head and first segment 
of the pereion confluent. Upper antenne 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. 
Tue 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 antenne 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 
antenne 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. 
