COPEPODS OF THE WOODS HOLE REGION 449 



portion and enlarged at its base ; posterior lobes on either side of this 

 sinus bluntly rounded and very flat. The fifth segment, genital seg- 

 ment and abdomen are considerably fused, but are indicated by lat- 

 eral sinuses and ventral grooves. The portion representing the fifth 

 segment is as long as the other two combined and carries on its 

 dorsal surface a pair of uniramose fifth legs. The portion repre- 

 senting the genital segment has strongly convex sides, to which are 

 attached the red spherical spermatophores ; the egg strings issue 

 from its dorsal surface close behind the fifth legs. The caudal rami 

 are leaf -shaped, as long as the abdomen and genital segment com- 

 bined, and acutely pointed. 



The first antennae are 6-segmented, the basal segment much thicker 

 than the others, but all of them short and almost without setae. The 

 second antennae are exceptionally stout, the terminal claw short, 

 strongly curved and turned inward at right angles to the basal seg- 

 ment, the claws of the two antennae touching each other. The second 

 maxilla is smaller than the second antenna or the maxilliped; its 

 terminal claw is narrow and as long as the basal segment, with an 

 accessory spine on its inner margin near the tip. The maxilliped is 

 even stouter than the second antenna, and its basal segment has a cor- 

 rugated swelling, against which the tip of the claw shuts down. 



The first and second legs are biramose, the rami 1-segmented; the 

 endopod of the first leg is conical and tipped with a short, non- 

 plumose seta; the exopod is a flattened lamina with six short and 

 blunt spines on the tip and outer margin. The third legs are ex- 

 ceptionally long and extend out side by side at right angles to the 

 ventral surface. The fourth legs are comparatively slender but are 

 more than half as long again as the whole body. The fifth legs are 

 two-thirds as long as the body and conceal the genital segment and 

 abdomen in dorsal view ; the bases of these legs are just beneath the 

 posterior margin of the dorsal plate. Total length, exclusive of 

 fourth and fifth legs, 7.5-8 mm. ; including fourth legs, 18.5-19 mm. 



Male. — Unknown. 



Remarks. — This species is easily identified by its large size and 

 by the exceptional length of the fourth and fifth legs. The host is 

 found in the southern part of the present area and ought to yield 

 other specimens of the new species. 



LERNANTHROPUS PAENULATUS Wilson 



Figure 282 



Lernan4hropus paenulatus Wilson, Proc. U. S. Nat. Mus., vol. 60, p. 51, pi. 6, 7, 

 1922. 



Occurrence. — Both sexes are found on the gills of the amber-jack 

 {Seriola lalandi) at Woods Hole. 



