132 TANAID®. 
ISOPODA. TANAIDZ. 
ABERRANTI4. 
Genus—LEPTOCHELIA. 
Leptochelia. Dana, U.S. Explor. Exped. p. 800. 
Tanais, pars. Kroyur, Nat. Tidssk. vol. iv. Li.gezore, Bidrag till Kin- 
nedomen om de inom Sverige och Norrige forekommande 
Crust. af Isopod. underord. och Tanaid. fam. p. 25. 
Generic character. Animal long and slender. First segment 
of pereion fused with cephalon, the following six segments sub- 
equal. Pleon consisting of six separate segments. Eyes pe- 
dunculated. Superior antenne long, and terminating in an 
articulated flagellum. Inferior antenne very short. First pair 
of gnathopoda long and chelate ; “ fingers slender and gaping” 
(Dana); second pair slender, feeble, and terminating in a long 
styliform dactylos. The five pairs of pereiopoda subequal in 
length, the three posterior pairs having the bases somewhat 
more robust than the two anterior pairs. Pleopoda, five an- 
terior pairs, biramose; posterior pair unibranched and multi- 
articulate. 
Tuts interesting genus holds an intermediate position 
between Tanais and Paratanais. It agrees with the 
former in the general contour of the body, and with the 
latter in the form of the second pair of gnathopoda as 
well as of the pereiopoda. The pleon has five distinct 
segments, each carrying a pair of pleopoda, as in Para- 
tanais, but it has only a single branch to the caudal pair 
of pleopoda attached to the sixth segment. The an- 
tenne are somewhat abnormal, since there is no distin- 
guishable peduncle. The superior pair have the first 
joint long and robust, the second not half as long as the 
preceding, the third and every successive joint is still 
shorter than the preceding, so that unless the first two 
joints of the peduncle be fused together, it is difficult to 
