COPEPODS OF THE WOODS HOLE REGION 547 



58. Both rami of fifth legs 3-segmented, armed with plumose setae; 



exopod of second antenna 8-segmented; fourth and fifth body 



segments fused; open ocean ? Lucicutia Giesbrecht, 1898 (p. 128) 



Both rami of fifth legs 3-segmented in female, one or both 2- 

 segmented in male; setae replaced by pectinated spines; 

 exopod of second antennae 5-segmented; muddy bot- 

 tom d" ? Platycopia G. O. Sars, 1911 



Endopods of fifth legs rudimentary or lacking; often the whole 



leg disappears on one or both sides 59 



59. Caudal rami at least six times as long as wide; fifth legs uni- 



ramose, 3-segmented in female; in male left leg 4-segmented, 



chelate, right 3-segmented; pelagic, at surface. 



d^ 9 Temora Baird, 1850 (p. 103) 



Caudal rami only three times as long as wide or less 60 



Caudal rami fully as wide as long or wider 73 



60. Middle segment of third endopod with 1, of fourth endopod 



with 2, setae; end segment of third endopod with 4, of fourth 

 endopod with 3, setae, all plumose; fresh-water plankton. 



9 Metaboeckella Ekman, 1906 



Middle segments of third and fourth endopods with 2, end seg- 

 ment with 7, setae 61 



Middle segments of third and fourth endopods with 1, end seg- 

 ment with 5, setae 71 



61. Terminal spine of second, third, and fourth exopods with its 



outer margin toothed or pectinated in both sexes; male with 



grasping antenna 62 



Terminal spine of second, third, and fourth exopods with its 

 outer margin smooth in both sexes; male without a grasping 

 antenna 68 



62. Both fifth legs uniramose, from 2- to 4-segmented 63 



One or both fifth legs biramose, with rudimentary endopod 64 



63. Fifth legs in female 3-segmented, symmetrical; in male 4-seg- 



mented, asymmetrical; genital segment flattened ventrally, 



without a process; Arctic plankton cT 9 Temorites G. O. Sars, 1900 



Fifth legs in female 3-segmented, asymmetrical; in male right 

 leg 2-segmented, left 3-segmented; genital segment with large 

 ventral process (South Atlantic) cf 9 Temoropia T. Scott, 1894 



64. Fifth legs symmetrical in female, endopods 1- or 2-segmented, 



exopods 3-segmented; asymmetrical in male, endopods 1- 



segmented, exopods 2-segmented 65 



Fifth legs symmetrical in female, endopods 1- or 2-segmented, 

 exopods 2-segmented; asymmetrical in male, segmentation 

 not as above 66 



65. Urosome 2-segmented in female; fourth and fifth metasome 



segments more or less completely separated, the fifth with 

 processes at posterior corners; fresh water (South Africa). 



c?" 9 Paradiaptomus G. O. Sars, 1895 

 Urosome 3-segmented in female; fourth and fifth metasome seg- 

 ments completely fused, the fifth with rounded corners, 

 without the posterior processes; fresh water (Mongolia). 



d^ 9 Hemidiaptomus G. O. Sars, 1903 



