COPEPODS OP THE WOODS HOLE REGION 459 



the spine is not on the outer margin but is terminal and lies between 

 the two outer setae. Total length, 3.85-4.15 mm. 



Male. — Carapace like that of the female; second and third seg- 

 ments two-thirds as wide as the carapace, narrowed anteriorly, widest 

 near the posterior margin ; fourth segment spindle-shaped, narrowed 

 both anteriorly and posteriorly, widest through the center. Fused 

 fifth and genital segment a little longer and narrower than the free 

 thorax, and tapered posteriorl3^ Abdomen 3-segmented, second seg- 

 ment as long as the first but narrower, anal segment less than half 

 the length of the second segment. Caudal rami longer than the anal 

 segment, four times as long as wide, divergent, each tipped with 

 three equal setae. Antennae, mouth parts, and legs like those of the 

 female. Total length, 2.3-2.5 mm. 



Remarks. — This genus can be distinguished from the preceding one 

 by its triangular cephalothorax, which is destitute of posterior lobes 

 and styliform processes. The species may be identified by the rela- 

 tive proportions of the fused fifth and genital segment. The finding 

 of several specimens in the spiracles of the few sting rays examined 

 would seem to indicate that the species is fairly common. 



KR0YERINA ELONGATA, new species 



Plate 31, l-p 



Occurrence. — A few specimens, all females, were obtained from 

 the gills of the great blue sharks {Galeus glaucus) captured on suc- 

 cessive days in August, 1926, in the fish nets on Marthas Vineyard. 

 The female holotype is U.S.N.M. No. 56673. 



Color. — Body a uniform snowy white; ^gg strings grayish. 



FeTnale. — General form elongate and narrow; carapace triangular 

 with rounded corners, one-fifth wider than long. The base of the 

 triangle forms the posterior margin of the carapace, is nearly 

 straight, and shows neither lobes, sinuses, nor styliform processes. 

 Second, third, and fourth segments about the same length but 

 diminishing slightly in width, the fourth segment a little more than 

 half the width of the carapace. Fused fifth and genital segment 

 wider than the free thorax, but not so wide as the carapace, eight 

 and a half times as long as wide, with straight sides and smoothly 

 rounded i^osterior corners. Abdomen one-sixth as long and half 

 as wide as the genital segment, 2-segmented, the anal segment 

 spindle-shaped and twice as long as the basal segment. Caudal rami 

 linear, five times as long as wide, each tipped with three minute setae. 



First antennae indistinctly 7-segmented, sparsely armed with 

 rather short spines; second antenna stout, terminated by a pair of 

 pinchers the digits of which are in contact at their base and overlap 

 at their tips. Second maxilla much shorter than in nasuta, but 



