NO. 19 NEW PARASITIC COPEPODS WILSON 7 



inner margin near the tip, with no spines. Each fifth leg consists 

 of a fingerhke process tipped with a seta and another seta in front 

 of the base of the process. These fifth legs stand out from the ventral 

 surface of the genital segment in such a way that they are invisible in 

 dorsal view. The drawing in figure 27 was made under a cover glass, 

 which turned the fifth leg sidewise and made it appear to project 

 beyond the lateral margin of the segment. 



Total length of male 4 to 5 mm. Length of cephalothorax 2.50 mm ; 

 width of same 2.60 mm. 



Remarks. — Superficially, in size and general appearance the females 

 are so similar to Nesippus occultus that they were first referred to 

 that species. The males, however, are extremely dissimilar, and on 

 closer examination the females revealed sufficient differences to consti- 

 tute a new species. The distinctive characters are the rectangular 

 lobes of the second thoracic segment, the isolated appearance of the 

 fourth segment, the slenderness of the genital segment and the length 

 of its posterior lobes, and the structural details of the appendages. 

 If the number of specimens obtained is any criterion, gracilis is a 

 much rarer species than crypturus. 



KR0YERIA DISPAR, n. sp. 



Plate 3, figs. 34-42 



Occurrence. — Three females belonging to this new species were ob- 

 tained from the gills of an unnamed shark. 



Type. — U.S.N.M. no. 64053 ; paratypes, U.S.N.M. no. 64054. 



The female. — Carapace one-half wider than long; cephalic area 

 triangular with all three sides convex, the base forming the frontal 

 margin and projecting in front of the lateral area. Posterior lobes 

 short and broadly rounded, slightly reentrant on the outer margin 

 near the tip and not quite reaching the posterior margin of the median 

 lobe. Styliform process straight and stout, just reaching the posterior 

 margin of the second segment. Second, third, and fourth segments 

 about the same length and width, which is less than half the width 

 of the carapace. Each of these segments carries a pair of dorsal plates, 

 and there is a fourth pair on the median lobe of the carapace. These 

 plates are small and closely adherent to the dorsal surface ; those of 

 each pair meet on the midline, are of a different shape from the other 

 pairs, and are much smaller than the surface to which they are 

 attached. 



The fused fifth and genital segment is slightly narrower than the 

 fourth segment anteriorly and is tapered posteriorly to the width of 



