436 



BULLETIN" 15 8, UNITED STATES N-ATIOKAL MUSEUM 



rower than the genital segment, its lateral margins semicircles. Gen- 

 ital segment narrowed into a short waist anteriorly, with rudiments 

 of both fifth and sixth legs, the latter much larger than the former 

 and acutely pointed, but unarmed, the fifth pair with spines. Ab- 

 domen 2-segmented, segments the same length, the basal one enlarged 

 through the middle; caudal rami as wide as long, each with three 

 apical setae and one on the inner margin, removed from the others. 

 Total length, 8-10 mm. 



Remarks. — The female may be identified by the fact that the cara- 

 pace is fully half the entire length; in the male the posterior lobes 

 of the carapace curve inward and the accessory lobes are longer than 

 wide. 



PANDARUS BICOLOR Leach 



Figure 274 



Pandarus Mcolor Leach, Supplement Encyclopedia Britannica, vol. 1, p. 405. 

 pi. 20, figs. 1, 2, 1816.— Wn-soN, Proc. U. S. Nat. Mus., vol. 33, p. 400, pi. 27, 

 1907. 



Occurrence. — Found on the fins of the smooth dogfish at Woods 

 Hole. 



Distribution. — British seas (Leach, Baird, Scott) ; Bohuslan, 

 Skager Rak (Olsson) ; Kattegat, North Sea (Kr0yer) ; coast of 

 Belgium (Beneden) ; Iceland (Hansen); Liguria (Brian). 



Color. — Female a creamy yellow, 

 the dorsal surface of the carapace, 

 the center of the dorsal plates of the 

 second, third, and fourth segments, 

 and two large spots connected across 

 the midline in the posterior part of the 

 genital segment an opaque chocolate 

 brown, becoming black in preserva- 

 tives. A Y-shaped spot through the 

 eyes and extending backward along 

 the midline is yellow and transparent. 

 The male is light yellow and trans- 

 parent. 



Female. — Carapace one-third the 

 entire length, widest posteriorly, the margin between the posterior 

 lobes deeply sinuate. Dorsal plates of second segment not reaching 

 beyond tips of plates on third segment; those on fourth segment 

 covering only half the genital segment, with a broad median sinus. 

 Genital segment elliptical, with broadly rounded posterior lobes; 

 sixth segment plate more than half the width of genital segment, cir- 

 cular, as wide as long ; caudal rami much shorter than the sixth seg- 

 ment plate, and widely divergent. Total length, 8-9 mm. 



Figure 274. — Pandarus Mcolor: a. 

 Female, dorsal; t, male, dorsal (af- 

 ter T. Scott) 



