COPEPODS OF THE WOODS HOLE REGION 571 



88. Exopod of second antenna made up of a single segment 89 



Exopod of second antenna made up of 2 segments 91 



Exopod of second antenna made up of 3 segments 93 



89. Neither ramus of first legs broadened, endopod tipped with 



stout claw, hooked at the tip; basal expansion of fifth leg 



large, with 4 setae; parasitic on land crabs-- ? Cancrincola Wilson, 1913 



One or both rami of first legs much broadened 90 



90 Both rami of first legs broadened; caudal rami lamellate, with 

 weak setae; fifth legs without basal expansion, end segment 



lanceolate; littoral, among algae cf 9 Porcellidium Claus, 1860 



First endopod broadened, exopod normal; caudal rami cyUndri- 

 cal with well developed setae; fifth legs with large basal 



expansion; Httoral, among algae c? ? lalysus Brian, 1927 



91. Body strongly depressed, all but last 2 segments with lateral 



lameUae; first exopod longer than the endopod 92 



Body strongly depressed, metasome and genital segments with 

 angular lamellae; first endopod much longer than exopod, 



broadened; muddy bottom, fiords 9 Idyella G. O. Sars, 1905 



Body little depressed, second, third, and fourth segments only 

 with lamellae; rami of first legs equ&l, both widened; fifth legs 

 long and narrow; brackish pools, in algae. 



cf 9 Chappaquiddicka, new genus (p. 198) 



92 Every body segment with anastomosing chitin bands and dorsal 

 projections on midline; corners of genital segment reaching 



caudal rami; littoral, sandy bottom d" 9 Peltidium Philippi, 1839 



Body segments without chitin bands or dorsal projections; 

 corners of genital segment scarcely reaching basal abdommal 

 segment; washed from dredgings 9 Eupeltidium A. Scott, 1909 



93. Proximal segment of first endopod longer than entire exopod; 



rostrum not visible dorsally 



Proximal segment of first endopod much shorter than exopod; 



rostrum large and conspicuous in dorsal view 95 



94 Fifth segment but little narrower than fourth; caudal setae 



very short; basal segment of fifth legs without outer process; 

 first antenna 7-segmented; littoral (New Zealand). 



cf 9 Xouthous Thomson, 1883 



Fifth segment abruptly narrowed to half the width of fourth; 

 caudal setae long; fifth legs with large outer process; first 

 antenna with 9 segments; littoral (Kerguelen Island). 



9 Machairopus Brady, 1883 



95 Distal segment of first endopod half as long as basal, with 2 



unequal terminal spines; metasome more than twice as wide 



as urosome; muddy bottom 9 Dactylopodopsls G. O. Sars, 1911 



Distal segment of first endopod twice as long as basal, with 3 



apical setae; metasome little wider than urosome; second leg , ,„^, 



modified in male; muddy bottom c?' 9 Danielssenia Boeck, 1873 



