454 BULLETIN" 15 8, UISriTED STATES NATIONAL MUSEUM 



fourth legs the two basal exopod segments have an inside seta but no 

 outside spine; the terminal segment has two spines and four setae. 

 The basal segment of the fourth endopod has an inner seta, the sec- 

 ond segment has both an inner and an outer seta, and a row of short 

 spines on the outer margin, the terminal segment has two or three 

 spines on the outer margin and two apical setae. Total length, 7-8 

 mm. Carapace and free thorax combined, 1.75 mm. Genital seg- 

 ment, 5 mm. long, 1 mm. wide. Ovisacs, 10 mm. 



Male. — Carapace one-third Avider than long; cephalic area some- 

 what pentagonal; styliform processes stout but only reaching the 

 middle of the second segment. Second and third segments about the 

 same width and length, fourth segment narrower and longer; fifth 

 and genital segment one-fifth longer than the free thorax, the same 

 width as the fourth segment anteriorly, but tapered posteriorly. 

 Abdomen 3-segmented, the segments diminishing in length and width 

 backward; caudal rami longer than the anal segment, ten times as 

 long as wide, each with three apical setae and a fringe of cilia on the 

 inner margin. The two basal segments of the fourth exopod have 

 an inner seta but no outer spine, the terminal segment has two apical 

 spines and four setae. The basal segment of the endopod has an 

 inner seta and a smooth outer margin ; the second segment has a seta 

 at each distal corner, and a row of small spines proximal to the outer 

 seta ; the terminal segment has three small spines on the outer margin 

 and two apical setae. All the swimming legs have a pair of acumi- 

 nate spines, one at each end of the short rib joining their bases across 

 the midline. Total length, 4^.5 mm. 



Remarks. — This species can be identified most quickly by the 

 3-segmented abdomen, which in the other two species has only a 

 single segment. The number of specimens recorded above shows that 

 it is at least a common species, although these large sharks are 

 captured only occasionally, 



KR0YERIA PAPILLIPES, new species 



Plate 30, a-i 



OcGWfT&rhce. — A female was taken from the gills of the hammer- 

 head shark {Sphyrna zygaena) in August, 1911, and six males and 

 females were taken from the gills of the tiger shark {Galeocerdo 

 arcticus), August 13, 1926. A female of this latter lot is the holo- 

 type of the species, U.S.N.M. No. 56672. Both sharks were cap- 

 tured in the fish nets on Marthas Vineyard. 



Color. — Body yellowish white, darker and more or less brownish 

 in the thicker parts of the cephalothorax and abdom^en; ovisacs 

 brown. 



Female. — Carapace one-fourth wider than long, with evenly 

 rounded lateral margins; cephalic area suborbicular, as wide as long; 



