702 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxv. 



4. Abdomen medium, about 0.25, wider than long; lobes on basal joints of posterior 



legs oval, and half the length of the legs indicus, p. 727 



5. Diameter of sucking disks, 0.1 to 0.12; abdomen large, 0.33, elongated, with 



lanceolate-acuminate lobes coregoni, male, p. 724 



C^. Carapace elliptical, considerably longer than wide. 



6. Sucking disks, 0.25, situated very far forward; abdomen narrow, ovate, cut far 



beyond the center; color a uniform black, lighter on the ventral surface. 



nlger, female, p. 714 



7. Sucking disks, 0.2, not far forward, but nearer the center of the carapace; 



abdomen wide, elliptical, cut barely to the center; color greenish yellow. 



pugeitensis, p. 711 

 W. Swimming legs without flagella. 



8. Carapace covering the whole of the abdomen; last thoracic segment with lobes 



overlapping the abdomen (gigantens of Lucas) purpureus, p. 723 



A'. Carapace lobes just reaching the base of the abdomen. 

 B. Anterior swimming legs with flagella. 

 C. Carapace orbicular, wider than long. 

 D. Abdomen broadly triangular; anal sinus not reaching halfway to the cen- 

 ter; legs extending beyond the carapace. 



9. Anal sinus narrow and slit like; anal papilhe subterminal; bases of antennae 



close to mid line of carapace versicolor, male, p. 716 



10. Anal sinus broad triangular; anal papillae lateral; bases of antennae widely 



separated viaculosus, p. 715 



1)'. Abdomen long elliptical; anal sinus cut fully to the center; lobes acumi- 

 nate; legs entirely covered by carapace. 



11. Anal sinus narrow; papillae basal coregoni, male, p. 724 



C. Carapace elliptical, considerably longer than wide; abdomen broadly ellip- 

 tical; alxlominal sinus short, well rounded. 



12. Sucking disks about 0.25; legs not nearly reaching the edge of the carapace. 



salmini, male, p. 720 



13. Sucking disks less than 0.25; legs reaching beyond the carapace. 



laticauda, male, p. 705 

 A^'. Carapace lobes not reaching the abdomen. 

 B. Anterior swimming legs with full-sized flagella. 

 C. Carapace orbicular, wider than long, covering three pairs of legs, almost 

 reaching the abdomen. 



14. Abdomen large, elliptical, cut beyond the center, with acute lobes; legs reach- 



ing beyond the edge of the carapace coregoni, female, p. 724 



15. Abdomen very small, orbicular; anal sinus short, lobes well-rounded; legs not 



reaching the edge of the carapace salmini, female, p. 720 



16. Abdomen medium, oval; anal sinus short, slit like, papillae subterminal; color 



variegated versicolor, female, p. 716 



17. Abdomen small, elliptical, not cut to the center, with rounded lobes; lobes on 



posterior legs large, hatchet-shaped africanus, p. 727 



18. Abdomen large, 0.63, cut beyond the center; papillae lateral, about one-quarter 



the distance from the base of the sinus; longitudinal ribs forked at the 



anterior end pho.vini, p. 728 



C Carapace elliptical, considerablj^ longer than wide. 



D. Abdomen broadly elliptical, not cut a third of its length, lol^es broadly 

 rounded; sucking disks less than 0.12. 



19. Carapace lobes short and entirely free from the thorax, with spaces between; 



teeth on basal plate narrow and sharp chromidis, female, p. 721 



20. Carapace lobes long and overlapping the thorax; teeth on basal plate wide and 



squarely truncated; posterior maxillipeds large, well-armed. 



laticauda, female, p. 705 



