8 PROCEEDESTGS OF THE NATIONAL MUSEUM vol. 121 



ture. Legs 2-4 with rows of spinules as indicated in figures. Leg 

 5 (see fig. 6) a lobe on posterior corner of thoracic segment 5 bearing 

 3 short setae. Leg 6 absent. 



Egg strings imiseriate, long. 



Male. — Body form as in figure 2. Total length 4.0 mm. Greatest 

 width 1.0 mm. Genital segment as long as wide (0.8 mm). Con- 

 figuration of body otherwise as in female. Caudal rami as in female. 



Oral area and cephalic appendages as in female. 



Legs 1-4 biramose. All rami 2-segmented. Spine and setal for- 

 mula as follows: 



seg. 1 

 seg. 2 



Legs 2-4 (figs 17, 18, and 19) armed as in figures. Terminal endopod 

 segment of leg 3 bearing a modified seta as sho\vn in figure 18. Ter- 

 minal endopod segment of leg 4 also wdth modified seta but differing 

 from that of leg 3 (compare figs. 18 and 19). Leg 5 a lobe with 3 

 setae along distal border and 1 seta near base of lobe. Segment 

 bearing leg 5 small and inconspicuous. Leg 6 (fig. 20) a broad lobe on 

 ventrodistal corner of genital segment bearing 3 setae, innermost 

 twice as long as outer 2. 



Remarks.- — ^This species differs from A^". pallida Wilson, A^. vermi 

 Scott, N. robusta (van Beneden), A^. atlantica Wilson, A^^. pilosa Pearse, 

 and N. macrocephalus Shiino by the nature of the spinules on segment 

 2 of the second antenna. In A^". aggregatus there is a patch of 10-12 

 prominent spinules on this segment whereas in the above-mentioned 

 species this patch is composed of 25-40 small spinules. Nemesis 

 tiburo and A^. versicolor differ from A^. aggregatus in the presence of a 

 row of fine spinules on segment 3 of second antenna in addition to 

 those on segment 2. 



Habitat: The parasites were foimd attached to the free end of 

 each gill filament nearest to the gill slit. The tissue at the site of 

 attachment was swollen and pale m color (normally red). Each 

 gill filament could carry as many as 8 copepods on its tip. 



The name aggregatus from Latin, meaning "clustered or united," 

 refers to the appearance of the species. 



Eudactylina aspera Heller, 1865 



Collections: From 8 specimens of Carcharinus maculipinnis; from 

 2 specimens of Rhizoprionodon acutus; from 1 specimen of Sphyrna 

 lewini; aU from Nosy Be. 



Habitat: Gill filaments. 



