COPEPODS OP THE WOODS HOLE REGION 355 



nae 3-seginented, prehensile; rami of first three pairs of legs and 

 exopod of fourth pair 3 -segmented ; endopod of fourth pair 1-seg- 

 mented; each fifth leg represented by two setae, unequal in length. 



KEY TO THE SPECIES 



1. Urosome 2-segmented, genital segment and abdomen separated 2 



Urosome 1-segmented, genital segment and abdomen completely 



fused ; caudal rami about half as long as urcsome elongatus (p. 355) 



2. Genital opening with 1 or 2 setae ; female with 2 ovisacs 3 



Genital opening without setae ; female with 1 ovisac 4 



3. Genital segment shorter than abdomen and caudal rami com- 



bined venustus (p. 360) 



Genital segment longer than abdomen and caudal rami com- 

 bined obtusus (p, 356) 



4. Caudal rami longer than entire urosome ; lappets on third seg- 



ment acuminate and reaching beyond end of genital seg- 

 ment speciosus (p. 358) 



Caudal rami three-fifths as long as urosome; lappets on third 



segment acuminate and not reaching end of genital segment 



danae (p. 359) 



Caudal rami half as long as urosome; lappets on third segment 



acute and reaching just beyond center of genital segment- ovalis (p. 359) 



1. Genital segment with a tooth at anterior end on ventral midline 2 



Genital segment rounded at anterior end, no tooth 3 



2. Genital segment longer than abdomen and caudal rami combined, 



with rounded lobes at its posterior corners obtusus (p. 356) 



Genital segment three-fourths as long as abdomen and caudal 

 rami, without lobes at its posterior corners venustus (p. 360) 



3. Inner margin of second segment of posterior antenna with a 



stout pointed tooth near its distal end 4 



Inner margin of second segment of posterior antenna smooth, no 



tooth near its distal end elongatus (p. 355) 



4. Caudal rami half as long as urosome; genital segment obovate, 



widest considerably behind center ovalis (p. 359) 



Caudal rami three-fourths as long as urosome; genital segment 



elliptical, widest at center danae (p. 359) 



Caudal rami as long as urosome ; genital segment notched on 



each lateral margin near jwsterior end speciosus (p. 358) 



CORYCAEUS ELONGATUS Claus 



Figure 214 



Corycaeus elongatus Claus, Die frei lebenden Copepoden, p. 157, pi. 24, figs. 3-4, 

 1863. — GiESBRECHT, Fauua und Flora des Golfes von Neapel, vol. 19, p. 

 659, pis. 4, 49, 51, 1892. 



Occurrence. — One female in surface tow on Georges Bank, Septem- 

 ber 15, 1874 ; both sexes in a vertical haul at Station 20048, Grampus, 

 east of Chatham. 



