558 BULLETIN 159, UNITED STATES NATIONAL MUSEUM 



159. Two pairs of lenses; rami of female fifth legs very unequal; the 



right fifth leg in male with weak chela, finger and thumb 



obtuse; open ocean cT ? Anomalocera Templeton, 1837 (p. 142) 



Only 1 pair of lenses; fifth legs biramose in female, rami 

 1-segmented; uniramose in male, 3-segmented, asymmetri- 

 cal, right leg without a chela (North Pacific). 



cf 9 Epilabidocera, new name " 

 Only 1 pair of lenses; right fifth leg in male with stout chela, 

 having a sharp-pointed finger and thumb; left leg unira- 

 mose 160 



160. Fourth and fifth metasome segments fused; first antenna of 



female 22-segmented; apical section of grasping antenna of 



male with 4 segments; open ocean cf ? Ivellopsis Claus, 1893 



Fourth and fifth metasome segments separated; first antenna 

 of female 24-segmented; apical section of male grasping 

 antenna with 2 segments; open ocean, cf 9 Pontella Dana, 1846 (p. 149) 



161. Rami of second antenna subequal, or exopod longer than endo- 



pod 162 



Endopod of second antenna much longer than exopod 163 



162. Fifth legs uniramose and 3-segmented in both sexes; urosome 



3-segmented in female, 4-segmented in male; exopod of 

 second antenna with 7 segments; open ocean. 



d^ 9 Neopontella A. Scott, 1909 

 Fifth legs biramose, rami 1-segmented in female, uniramose 

 and 3-segmented in male; urosome 5-segmented in male; 

 exopod of second antennae 5-segmented; open ocean. 



cf 9 Parapontella Brady, 1878 



163. Urosome asymmetrical; fifth legs in female biramose, rami 



1-segmented, exopod twice as long as endopod; in male 

 uniramose and 3-segmented; open ocean. 



cf 9 Pontellopsis Brady, 1883 (p. 157) 

 Urosome symmetrical; fifth legs in female biramose, 1-seg- 

 mented, exopod four times as long as endopod; in male 

 uniramose and 4-segmented; open ocean. 



cT 9 Pontellina Dana, 1852 (p. 155) 



164. Head with one pair of dorsal lenses; fifth legs biramose in 



female, rami 1-segmented and unequal; right leg uniramose 



in male, with chela; open ocean- cf 9 Labidocera Lubbock, 1853 (p. 144) 



No dorsal lenses; fifth legs obsolete in female; in male biramose, 

 rami 1-segmented, no chela; urosome in female 2-segmented, 

 in male 3-segmented; littoral (Tasmania). 6^9 Diarthropus Brady, 1918 



No dorsal lenses; fifth legs not segmented as above 165 



165. Fifth legs biramose in one sex, uniramose in the other 166 



Fifth legs biramose in both sexes 168 



Fifth legs uniramose in both sexes 169 



Fifth legs biramose, rami 1-segmented in female; male un- 

 known; exopod of second antenna 8-segmented; first an- 

 tennae reaching beyond caudal rami (North Pacific). 



cf Pseudolovenula Marukawa, 1921 



i« Paralabidocera McMurrich, 1916, was preoccupied by Wolfenden in 1908 for a very different genus of 

 copepods (see 167 in this key). This new name is substituted for McMurrich's genus. 



