452 BULLETIN 15 8, UNITED STATES NATIONAL MUSEUM 



Anterior portion of dorsal plate quadrangular, a little wider than 

 long, and a half wider than the carapace; posterior portion nar- 

 rower than the anterior, strongly tapered posteriorly and bluntly 

 rounded. Genital segment small, with rather flat sides; abdomen 

 nearly quadrangular, as wide as long; caudal rami short rounded 

 knobs, less than one-fifth the length of the abdo- 

 men. Third legs widely separated, very large, 

 and hood-shaped; fourth legs biramose, divided 

 to their base, the endopod only one-third the 

 length of the exopod, both rami foliaceous and 

 bluntly rounded. Length, without fourth legs, 

 4—5 mm. ; with fourth legs, 6-7 mm. 



Male. — Short and stocky ; carapace as wide and 

 about as long as the body, with smoothly convex 

 margins. Body obovate, one-fifth longer than 

 wide, bluntly rounded posteriorly; genital seg- 

 FiGDEE 284.— Lernan- ment narrower than the free thorax; abdomen 

 thro pus hrevoor- much narrower than the genital segment; caudal 

 tme: Female, dor- ^.^j-^^^ ^gj.y small. Third and fourth legs cylindri- 

 cal, uniramose, bluntly pointed, third pair only 

 half as long as the fourth. Length, excluding fourth legs, 2 mm. ; 

 including fourth legs, 2.75 mm. 



Remarks. — This species was originally found in Vineyard Sound 

 and is comimon there upon the gills of the menhaden. Beaufort is 

 the only known locality outside the present area, as recorded above. 



Family EUDACTYLINIDAE 



Genus KR0YERIA Beneden, 1853 



Female. — Head fused with the first segment and covered with a 

 carapace, having lateral and median posterior lobes. In the sinus 

 between the two lobes on each side is a movable styliform process, 

 attached on the dorsal surface and extending backward along the 

 side of the free thorax. Second, third, and fourth segments free, 

 without processes, but each with a pair of dorsal plates; fifth and 

 genital segments more or less completely fused, elongate, and cylin- 

 drical or slightly flattened. Abdomen short, 1- to 3-segmented; 

 caudal rami long, narrow, and armed with setae. First antennae 

 6- or 7-segmented ; second antennae chelate ; maxillipeds with power- 

 ful terminal claws; four pairs of biramose swimming legs, the rami 

 3-segmented ; egg strings linear. 



Male. — Carapace like that of female; second and third segments 

 about the same size, fourth segment often enlarged ; fifth and genital 

 segments fused, but much shorter and narrower than those of the 

 female. Abdomen relatively longer and 3-segmented; caudal rami 



