572 BULLETIN 159, UNITED STATES NATIONAL MUSEUM 



96. Fifth legs made up of from 2 to 4 segments 97 



Fifth legs made up of a single segment 119 



Fifth legs obsolete or represented by a seta 120 



Fifth legs unknown; first antennae 9-segmented, laminate, 



without a sensory filament; second endopod 3-segmented, 

 armed with spines and plumose setae; pelagic (Antarctic 



Ocean) 9 Dactylopina Brady, 1910 



Fifth legs unknown; first antennae 10-segmented, cylindrical, 

 with a sensory filament; second endopod 1-segmented, 

 armed with setae, no spines; littoral (New Zealand). 



9 Flavia Brady, 1899 



97. Fifth legs made up of 4 segments, males 98 



Fifth legs made up of 3 segments, males 99 



Fifth legs made up of 2 segments, both sexes 100 



98. Middle segment of first exopod much the longest; third endopod 



modified for prehension; exopod of second antennae 2-seg- 

 mented, armed with 6 setae; littoral, among algae. 



d^ Microthalestris G. O. Sars, 1905 (p. 204) 

 The 3 segments of first exopod subequal; third endopod not 

 modified for prehension; exopod of second antenna 3-seg- 

 mented and armed with 5 setae; oyster washings (Ceylon). 



cf Parastenhelia Thompson and Scott, 1903 



99. First legs prehensile; second basipod longer than the 2-seg- 



mented endopod; middle exopod segment longer than the 

 first and third segments combined; littoral, shallow water. 



(^ Eupelte Claus, 1860 

 First legs natatory; second basipod not lengthened; the 3 exopod 

 segments about the same length; caudal rami very long and 

 narrow; muddy bottom, shallow cf Herdmania Thompson, 1893 



100. Fifth legs linear, basal segment without inner expansion 101 



Fifth legs stout, basal segment with inner expansion 105 



101. Body depressed; metasome and genital segments with lamellae 



and dorsal projections; first endopods widened, shorter than 



exopods; littoral, sandy bottom cf ? Peltidium Philippi, 1839 



Body depressed; metasome and genital segments with lamellae 

 without projections; both rami of first legs widened, exopods 

 the shorter; muddy bottom, shallow 9 Idyella G. 0. Sars, 1905 



Body depressed; metasome and genital segments with lamellae, 



without projections; neither ramus of first legs widened 102 



Body cylindrical, without lamellae or projections 103 



102. Rami of first legs subequal; middle segment of first exopod 



three times as long as end segment, the latter natatory, 



with setae; dredge washings cT 9 Paralteutha T. Scott, 1912 



First exopod more than twice as long as endopod, its middle 

 segment five times as long as end segment, the latter pre- 

 hensile, with claws; littoral, muddy bottom 9 Eupelte Claus, 1860 



103. Caudal rami 15 times as long as wide; the 3 segments of first 



exopod about the same length; first legs natatory, with 



setae; muddy bottom, shallow 9 Herdmania Thompson, 1893 



Caudal rami as wide as long; end segment of first exopod 



shorter than either of the 2 other segments 104 



