COPEPODS OF THE WOODS HOLE REGION" 



425 



extending across the body. Genital segment larger than carapace; 

 abdomen entirely concealed, 1-segmented, attached to ventral sur- 

 face of genital segment. First four pairs of legs biramose, rami of 

 first and second pairs 2-segmented, of third and fourth pairs 1- 

 segmented; fifth legs obsolete. 



Male. — Carapace longer than wide; second segment with small 

 lateral plates, third and fourth segments without dorsal plates; gen- 

 ital segment much smaller than carapace, quadrilateral, the fifth 

 legs prominent on the lateral margins near the posterior corners. 

 Abdomen large, 1-segmented, entirely visible behind the genital seg- 

 ment. Rami of first four pairs of legs 2-segmented, segments of 

 fourth pair more or less fused ; maxilliped with stout claw shutting 

 against a pair of corrugated knobs. A single species in this area. 



PERISSOPUS COMMUNIS Rathbun 



Figure 267 



Perissopus comynnnls Rathbun, Proc. U. S. Nat. Mus., vol. 10, p. 560, pis. 29, 30, 

 1887.— Wilson, Proc. U. S. Nat. Mus., vol. 33, p. 354, pis. 17, 18, 1907. 



Occurrence. — Found on the gills and fins of the dusky shark, the 

 brown shark, and the smooth dogfish, all captured at or near Woods 

 Hole. 



Figure 267. — Perissopus communis: a. Female, dorsal; 6, 

 male, dorsal 



Distribution. — Not found outside the present area except as men- 

 tioned below. 



Color. — Body a light yellowish white, without pigment markings. 



