THE CRUSTACEA OF NEW JERSEY. loi 



maxillipeds small, weak, terminal and basal joints subequal, end 

 in two claws same size covered with stiff hairs. Second maxilli- 

 peds considerably larger and stouter, terminal claw about three- 

 fourths length of basal joint. On inner surface of latter, oppo- 

 site tip of claw, pair of long blunt spines, some distance apart 

 and so situated that when claw closes down on basal joint it shuts 

 in between them and is locked securely in place. All four joints 

 of legs biramose, rami of first three pairs two- jointed, of fourth 

 pair one-jointed. In first pair exopod considerably larger than 

 endopod, basal joint three times length of terminal and nearly 

 twice as wide, and endopod joints about equal. In second and 

 third legs basal joints enlarged and connected across mid-line 

 by wide lamina, larger in third pair than in second. Rami of 

 second pair about same size, joints unequal, in exopod basal 

 joint twice size of terminal and in endopod terminal joint more 

 than twice size of basal. Rami of third legs equal and four 

 joints nearly same size. Fourth legs and basal joints well 

 separated, without connection across mid-line, rami one-jointed 

 and rudimentary, exopod three times size of endopod, both 

 armed with short spines and without plumose setae. Color 

 variegated yellow and gray. Total length 7 mm. 



Description of male. — Carapace much larger in proportion, 

 more than twice width of rest of body and about same length. 

 Grooves and divisions as in female. Lateral plates on fused 

 second and third segments plainly visible just inside posterior 

 lobes of carapace. Dorsal plates of fourth segment ver}' rudi- 

 mentary, no larger than lateral plates just mentioned, barely 

 overlapping base of genital segment. Latter subquadrangular, 

 with slightly rounded sides, hind angles armed with sharp spines, 

 and hind edge with wide central sinus with divergent sides 

 sliowing most of dorsal surface of abdomen. Margin on either 

 side of sinous sigmoid, almost exastly as in Perissopns. Abdomen 

 as in female, also anal laminse. First antennae longer than in 

 female, more densely armed with setae. Second antennae much 

 enlarged, and terminal claw projects well in front of carapace. 

 Other appendages as in female, except that in all spines and claws 

 longer and sharper. Basal joint of exopod of first legs some- 



