428 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.38. 



All. Fifth legs one-segmented \ L2. 



Fifth legs two- to four-segmented \ L3. 



A 1-. Firsl leg not prehensile. Caudal setae modified. One egg sac. Muddy I 



toms, 20 fathoms Zosime. 



First leg prehensile. Inner rami of second legs three-segmented, modified. 

 Fifth leg an inconspicuous plate in male. Two egg sacs. 3 to 30 fathoms. 



Muddy 1m it 1 1 mis or algae Sfnilu I in i pari . 



A L3. Fifth leg four-segmented ; first antenna nine-segmented A 14. 



Fifth leg less than four-segmented \ 15. 



A 11. Outer ramus firsl leg with segments approximately same length. Inner rami 



alike in sexes. Washings from muddy dredgings Parastenhelia (male). 



Outer ramus first leg with the middle Begment much the larger. Inner ramus 

 of third leg unlike in the sexes. Not more than 0.5 mm. long. Littoral, 



among algae Wicrothalestris I male). 



A L5. Fifth foot three-segmented A 16. 



Fifth foot two-segmented AIT. 



A Ki. Furca extremely long and narrow. First leg not prehensile, but terminal seg- 

 ment with a finger-like projection. First antenna nine segmented. Pelagic, 



muddy bottoms //* rdmania (male). 



Furca uol extremely long and uarrow. First leg prehensile. Body depressed. 



Littoral, 2 to 20 fathoms Eupelte. 



A 17. Fifth legs narrow, linear \ L8. 



Fifth legs not narrow and linear. Basal segment much expanded \ 20. 



A L8. Body short, oval, and much flattened. Furca not reaching beyond posterior 

 expansions of body segments, and narrow. Inner segments of first legs broad. 



Littoral, sandy bottom Peltidium. 



Bod) uot oval and much flattened \ 19. 



A 19. Furca very long and narrow. First foot not prehensile, but terminal segment 

 with a finger-like projection. First antenna uine-segmented. Muddy bot- 

 toms, 30 i" H> fathoms //< rdmania i female 



Furca not very long and narrow. First fool prehensile, the basal segment very 

 broad, the terminal one narrow. Firsl antenna eight segmented. Somewhat 



like Cyclops. 10 to 30 fat In in is. muddy hut torn Idyi I In. 



A 20. First antenna five-segmented. First leg not prehensile. Inner ramus of sec- 

 ond leg two-segmented in male and modified; three-segmented in female. 



<)ur egg sac. Brackish mouths of rivers, and pelagic Danu lss< nia. 



First antenna six- to nine-segmented. First feet prehensile \ 21. 



A '_' I . Inner ramus of seem id legs t wo-segmented, modified in male, also with a spine. 

 Body dilate and depressed in front. First antenna six-segmented. 6 to 20 



fathoms, among algae and hydroids Dactylopodella. 



Inner ramus of second legs not modified in the \ 22. 



A 22. Inner rami first legs shorter than the outer rami. Twoeggsacs. First antenna 



eight-segmented. Brackish pools, muddy bottom Delavalia. 



Inner rami first legs longer than the outer rami V 23. 



A _':'.. Outer rami of first legs with the three segments about the same size. Inner 

 rami of all le^s alike in the sexes. Washings from muddj dredgings. 



Parastt nhelia feint 

 Outer rami of first Iegswith the middle segment much the longest of the three. 

 Not more than 0.6 mm. long. Inner ramus of third leg modified in male 



Littoral, among algae Wicrothalestris (female 



A _' I Outer rami of. firsl leg one- to two-segmented. Prehensile A '_'•">. 



Outer rami of firsl leg always three-segmented A 28. 



A 25. <>uter rami of £rst legs longer than the inner \ -<i. 



(»uter rami or first lege shorter than the inner (one-segmented in Parawest- 

 woodia nobilis) A L'7. 



