new Parasitic Gopepods on Fish. 367 



being described by Kroyer* from a male specimen obtained 

 on a large shark in the Atlantic, I here give a short account 

 of the female, which seems, without doubt, to be the same 

 species, taken from a small shark at Aden, which I was 

 fortunate enough to be able to examine immediately after its 

 capture, before the parasites had been washed off, finding two 

 mature females on the surface of the pectoral fin. The 

 description of Kroyer is very full, so that it is unnecessary to 

 enter into too great detail, only to point out the chief differ- 

 ences which appear. 



In outward form the dorsal plate covering the last thoracic 

 segment was much less apparent ; the genital segment, 

 though of almost equal proportional size to that of the male, 

 had extending between the posterior processes a much 

 shorter Particulate abdomen, the first joint of which was 

 rounded, slightly broader than long, the second being oval, 

 more than twice as long as the first, giving off two caudal 

 plates of an elongated oblong form, terminating in three 

 large plumose bristles and a small outer one. On minute 

 exam ination the posterior lobe of the carapace was seen to 

 have on either side four small teeth, and laterally there are 

 three others. The dentations at the posterior border of the 

 genital segment are bicuspid, and those on the elongated 

 portion are larger than the ones represented by Kroyer. The 

 posterior antennae are larger than in the male; the second 

 maxiiliped has a very short robust terminal claw, bearing a 

 hair on the inner surface near the base. The first two perseo- 

 pods do not vary, but in the third the detail seems to be 

 somewhat different : the outer paddle is large and has three 

 distinct joints, the first having on its inner border a long 

 plumose hair, on the outer border, which is ciliated, there are 

 two short thick bristles, the lower one being the longer; the 

 second joint has a plumose hair on the inner border and one 

 short bristle on the outer, on it is seen one reniform body; 

 the third joint bears two reniform bodies and on the inner 

 border are six plumose hairs : the inner paddle has an elon- 

 gated stalk-like joint and the final one bears five distinct 

 plumose hairs; the glandular (?) apparatus described by 

 Kioyer is also seen. Fourth peraeopods very rudimentary, 

 the proportional size being given in the Plate. On the 

 genital segment three bright red pigment-spots on either side 

 are very apparent. 



Length 7 nnllim. 



* ' Bidrag til Kundskab,' L863, pp. 165-168. 



