28 U.S. NATIONAL MUSEUM BULLETIN 23 6 



I failed to find a satisfactory grouping of the known males on which 

 to base a key. The following key has been adopted from Lindberg, 

 1953, but, because several species have been described since the 

 publication of his paper, some of the genera defined therein need 

 reconsideration. The genera Neocyclopina Herbst, 1952, and Meta- 

 cyclopiiia Lindberg, 1953, can be immediately singled out: Neocylopina 

 because of the reduction of the segmentation of legs 1 to 4; Meta- 

 cyclopina because of the aberrant shape of the body. Both, never- 

 theless, have been included in the following key. 



Key to the Genera of Cyclopinidae 



1. Endopodite of antenna 1-segmented, so that the whole antenna is composed 



of 3 segments. At least 2 of the appendages of the endopodite of leg 4 



reduced, represented by short spines Pterinopsyllus Brady 



Endopodite of antenna 2-segmented, whole antenna composed of 4 segments. 

 Appendages of endopodite of leg 4 normally developed setae or spines . . 2 



2. Proximal segment of leg 5 fused to 5th thoracic somite, so that leg 5 is 



composed of 1 free segment, bearing 4 or 3 appendages. External seta 

 of proximal segment, if present, inserting on slight ridge on ventral aspect 



of 5th thoracic somite 3 



Proximal part of leg 5 free from 5th thoracic somite, present as 1 or 2 free 

 segments, bearing an internal spine or external seta; leg 5 consequently 

 composed of 2 or 3 free segments 4 



3. Free segment of leg 5 with a total of 4 appendages . Paracyclopina Smirnov 

 Free segment of leg 5 with a total of 3 appendages . Cyclopetta G. O. Sars 



4. Leg 5 composed of 2 free segments 5 



Leg 5 composed of 3 free segments 12 



5. Terminal segment of leg 5 with 3 appendages 6 



Terminal segment of leg 5 with 4 or 5 appendages 8 



6. Armature of terminal segment of leg 5 composed of 3 spines. 



Cyclopidina Steuer 



Armature of terminal segment of leg 5 composed of 2 spines flanking a 



median seta 7 



7. Abdomen short, antennule 19-segmented. Endopodite of maxillipede long. 



All setae of furcal rami inserting apically Procyclopina Herbst 



Abdomen slender, antennule 10- to 13-segmented. Endopodite of maxilli- 

 pede short. At least one of the setae of the furcal rami inserting along 

 external margin of furcal ramus (compare also Cyclopina vachoni NichoUs) . 



Cyclopina Claus 



8. Terminal segment of leg 5 with a total of 5 appendages. 



Cyclopicina Lindberg 

 Terminal segment of leg 5 with a total of 4 appendages 9 



9. Exopodite of mandible 3-segmented 10 



Exopodite of mandible 4-segmented 11 



10. Endopodites of legs 1 to 4, 2-segmented, exopodites of legs 1 and 4, 2-seg- 



mented, of legs 2 and 3, 3-segmented Neocyclopina Herbst 



Exopodites and endopodites of legs 1 to 4 all 3-segmented. 



Cyclopinopsis Smirnov 



11. Segment 2 of endopodite leg 1 with 1 internal seta; segment 3 with a total 



of 5 setae Hemicyclopina Herbst 



