NO. 3570 PANDARIDAE — CRESSET 45 



length. Dorsal thoracic plates present on segment 4 and similar to 

 those of female. Genital segment with posterior corners produced to 

 form lobes serrate on posterior border (see fig. 212). Genital segment 

 slightly longer than wide (2.8 by 2.3 mm). Abdomen 2-segmented 

 and without dorsal plates. Caudal rami as in female. 



Oral area as in female. Legs 1-3 as in female except for a modifi- 

 cation on endopod of leg 3 (fig. 213). This appendage may be used 

 in the transfer of spermatophores to female. Leg 4 (fig. 214) with 

 rami 2-segmented and not modified in form of lamellae. Spine and 

 setal formula of less 1-4 as follows: 



Leg 5 (fig. 215) located at the midpoint of the lateral margin and 

 composed of an outer lobe with 2 setae (outer plumose, inner naked) 

 and an inner lobe with a single naked setae. Leg 6 (fig. 216) near 

 junction of abdomen and genital segment and consisting of a small 

 process bearing a single naked spine. 



Spermatophores (fig. 217) attach to female and cross to opposite 

 seminal receptacle as in other members of the family. It is less 

 obvious in this group since the spermatophores lie side by side in 

 close proximity to each other. Figure 217 shows one spermatophore 

 removed to reveal neck of the other spermatophore crossing to recep- 

 tacle of other side. 



Color cream white as in female and devoid of pigmentation. 



Discussion. — This parasite seems to be specific to sharks of the 

 genus Alopias. I have examined material from the Indian Ocean 

 and Pacific and it may well be found tliroughout the range of the 

 host genus. This species is easily separated from the known members 

 of the genus by the shape of the genital segment and nature of the 

 dorsal thoracic plates. It is found on the body surface of the host 

 and, from my own experience, seems to favor the undersurface of 

 the host in the region of the cloaca. The description of the male 

 should give pertinent information regarding the nature of the lesser 

 known males of other species of this genus. The modification of the 

 endopod of leg 3 is quite distinct. It is interesting to note that the 

 male and female are much more alike than in membei's of group I 

 of this family. This may prove to be a consistent difference between 

 these two groups. 



The word discrepans is from Latin, meaning "to differ." 



