THE MOUNT DESEKT EEGION 219 



2 First legs more or less transformed (a 



few exceptions). Female reproductive 

 openings ventral. Mouthparts not re- 

 duced in number, 5 pairs of legs pres- 

 ent. First antennae of male usually 



subchelate. Rarely parasitic Harpacticoida 



The above characters not combined ... 3 



3 Mandibles wanting 4 



Mandibles present 5 



4 Only the mandibles wanting Cyclopoida 



Other mouthparts also wanting 8 



5 Mouth more or less adapted to suction. . . 6 

 Mouth and mandibles adapted for biting . . 7 



6 Last cephalothoracic segment fused with 



genital segment 9 



Last cephalothoracic segment distinct . . . Cyclopoida 



7 Maxilliped of 2 or more segments, not 



prehensile. Eggs not carried in a brood 



pouch Cyclopoida 



Maxmillipeds of not more than 4 seg- 

 ments. Eggs carried in a dorsal brood 

 pouch or externally, in which case the 

 maxillipeds are prehensile Notodelphyoida 



8 Head and mouth present, sexes similar . . Monstrilloida 

 Head and mouth replaced by absorptive 



processes in female. Male a pygmy 



attached to female Herpyllobii 



9 Male relatively large and independent of 



the female Caligoida 



Male a pygmy, often attached to female . . 10 

 10 Female large, usually elongate. Parasites 



of fishes. Male attached to female .... Lernaeopodidea 

 Female less than 2 mm. long. Parasites 



of Crustacea. Male not attached to 



female Choniostomata 



Tribe CALANOIDA 

 Subtribe AMPHASCANDRIA 



In this subtribe and the following I consider it advisable to 

 greatly reduce the number of families given by G. 0. Sars 

 (1901-1902, p. 8-49). The following arrangement depends 

 largely on the structure of the natatory legs. 



