3874 O. Harger—Isopoda from New England. 
Chiridotea,* gen. nov. 
First three pairs of legs terminated by prehensile hands, in 
each of which the carpus is short and triangular, the propodus 
is robust and the dactylus capable of complete flexion on the 
pro Antenne with an articulated flagellum. Head 
dilated laterally. Operculum vaulted, with two apical plates. 
is genus is founded on Ch. ceca (Idotea ceca Say), which 
occurs on this coast from Florida to Halifax, Nova Scotia. 
It includes Ch. Tujisii (Idotea Tufisit Stimpson), of the New 
England coast from Long Island Sound to the Bay of Fundy, 
and, as constituted above, would also include Ch. entomon 
(/dotea entomon Bosc.), from the Baltic and other European local- 
ities, and Ch. Sabini (Idothea Sabini Kroyer), from the Arctic. 
e above mentioned species ought certainly to be separated 
from Idotea tricuspidata Desm., which may properly be regarded 
as the type of the genus Jdotea Fabr. 
Synidotea,t gen. nov. 
Astacilla Americana, sp. nov. 
Body nearly uniform in size throughout in the female, with 
the fourth thoracic segment narrow in the male, tuberculated. 
Head united with the first thoracic segment, and, together with 
slightly surpassing the second segment of the antennz in the 
female, nearly attaining the middle of the third in the male; 
basal segment swollen, nearly as long as the next two which 
are much more slender, last or flagellar segment shorter than 
the peduncle in the female, longer than the peduncle in the 
male. Antenne about three-fourths as long as the body, 
fourth segment longest, then the fifth and third; first two seg- 
ments short; flagellum three-jointed, short. First thoraci¢ 
* From xép, a hand, and Idotea. + From ctv, with or together, and Idotea. 
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