6 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 121 



Family Eudactylinidae Yamaguti, 1963 



Nemesis lamna Risso, 1826 



Collections: From 2 specimens of Isurus oxyrinchus at stations 296 

 and 310; from 2 specimens of Isurus species and 1 specimen of Car- 

 charodon carcharias from Durban. 



Habitat: Gill filaments. 



Nemesis versicolor Wilson, 1913 



Collections: From 12 specimens of Carcharinus maculipinnis from 

 Nosy Be. 



Habitat: GUI filaments. 



Nemesis robusta (Beneden, 1851) 



Collections: From 1 specimen of Sphyrna mokarran at station 409; 

 from 2 specimens of Sphyrna leioini and 4 specimens of Carcharinus 

 leucas from Nosy Be. 



Habitat: Gill filaments. 



Nemesis aggregatus, new species 



Figures 1, 2, 6-20 



Collections: From 5 specimens oi Alopias vulpinus at stations 109, 

 1 10, 115, 288, and 289. Material from station 288 designated as types. 

 Holotype, female, USNM 113291. Allotype, male, USNM 113292. 

 Paratypes female and male USNM 113293. 



Female. — 'Body form as in figure 1. Total length 4.5 mm. Greatest 

 width 1.5 mm. Cephalon slightly longer than wide (1.3 by 1.2 mm), 

 comprising nearly one-third of body length. First pedigerous segment 

 (2nd thoracic segment) fused with head. Thoracic segments 3-5 free, 

 about equal in length (0.85 mm). Thoracic segment bearing leg 5 free, 

 not combined to form genital segment (fig. 6). Genital segment wider 

 than long (0.7 by 0.4 mm), often with spermatophores attached at 

 posterior corners (fig. 6). Abdomen 3-segmented, segments measuring 

 140/z, 103;i, and 140/i respectively. Caudal rami (fig. 7) about twice 

 as long as wide (85/i by 40;u), each with 6 posterior setae. All setae of 

 about equal length, 2 broad and blunt as in figure. 



First antenna (fig. 8) of 12 segments, bearing short setae. Second 

 antenna (fig. 9) in form of claw, terminal segment with 2 short setae. 

 Second segment with patch of 10-12 short, broad, spinules on inner 

 surface. Mouth tube and mandible as in other members of genus. 

 First maxilla (fig. 10) biramose, each ramus with 2 terminal setae. 

 Second maxOla, in general, as in other members of genus. Tip armed 

 as in figure 11. MaxUliped (fig. 12) in form of stout claw. 



