186 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



length of the metasome; caudal rami longer than wide. First an- 

 tennae 8-segmented ; chela of maxillipeds very powerful and almost 

 spherical, armed with coarse spines. Exopod of first legs tipped 

 with three subequal pectinate claws, with no spines or setae; basal 

 expansion of fifth legs with only three marginal setae; distal 

 segment with five setae, the inner one very small. Total length, 

 0.75-1 mm. 



Male. — Larger than the female, with a narrower urosome ; chela of 

 first antennae with an almost spherical hand and a simple dactylus. 

 Exopod of third leg exceptionally large, its basal segment as long 

 as the two distal segments combined, all three armed with long thick 

 spines, and fringed with small teeth on their outer margins. Basal 

 segment of fifth legs rudimentary, without an inner expansion ; 

 distal segment elongate, quadrangular, its inner apical seta short. 

 Total length, 0.9-1.1 mm. 



Remarks. — This species, like the preceding, is very well distributed 

 through the present area. It may be recognized by its larger size, by 

 the absence of the transverse dorsal bands and all other pigment 

 markings, and by the swollen chela on the maxillipeds. 



HARPACTICUS UNIREMIS Kri0yer 



Figure 126 



Harpacticus uniremis Kr0yer, Gaimard's voyage en Scandinavie, Atlas, pi. 43, 

 fig. 1, a-p, 1845. — Sars, Crustacea of Norway, vol. 5, p. 51, pi. 29, 1904. 



Occurrence. — Both sexes were obtained in large numbers from 

 Quisset Pond, Falmouth, and Penzance Pond, Woods Hole, in July, 

 1925. 



Distrihution. —^v'lti^h. Isles (Brady) ; Kiel Bay (Giesbrecht) ; 

 Mediterranean (Glaus) ; Norwegian coast (Sars, Kr0yer) ; Arctic 

 Ocean (Wille^T^) ; Adriatic (Pesta, Grandori) ; Polar islands, Scottish 

 coast (T. Scott) ; Bering Sea (Poppe) ; Gulf of Genoa (Brian) ; 

 Narragansett Bay (Williams). 



Color. — Body yellowish gray, showing a variable greenish tinge, 

 with transverse bands of orange-yellow on the dorsal surface, not 

 reaching the lateral margins; two bands on the cephalothorax, one 

 band at each of the posterior margins of the second, third, and fourth 

 metasome segments and the second and third abdominal segments, and 

 a small spot on either side of the genital segment close to the lateral 

 margin. 



Female. — Body somewhat depressed, with the epimeral plates of 

 the metasome expanded laterally, their posterior corners forming an 

 acute angle; fifth segment but little narrower than the fourth; 

 urosome segments with a fringe of coarse spinules on their posterior 

 margins on the ventral surface; caudal rami wider than long, with 



