106 PROCEEDINGS OF THE NATION" AL MUSEUM vol.84 



ward from near the hind angle on each side; counting inward the 

 fourth seta on each side is set slightly behind seta 3 or 5. 



Transition to the full number of dorsal crests occurs on segment 12. 



Primary and secondary crests extending from the front margin of 

 the posterior subsegments to the hind margin, the crests on the 

 anterior segments subequal in size, but on the middle and posterior 

 segments the crests are distinctly differentiated ; surface between and 

 on the sides of the crests with strong raised reticulations, the top of 

 the crests of uniform height and moderately shining; the setae at the 

 ends of the primary crests are short, those on the posterior segments 

 not over a third as long as the crests. 



Poriferous carinae hardly more prominent than the dorsal crests ; 

 on the posterior segments the impressed poriferous area occupies 

 only the front half of the lateral margin, but on the other segments 

 almost the entire margin is included and the impression is elongate- 

 elliptic in shape. 



Last segment rather short, broadly truncate at apex, when viewed 

 from above; surface without ridges but with six tuberculate setae 

 in a biarcuate row close to the hind margin, from the thickened 

 apical portion of which the two long papillate hairs project. 



Anal valves slightly convex, the margins thin and strongly ele- 

 vated. 



Males with the gonopods erect, the apex of each bent sharply 

 laterad to form a long, nearly horizontal, and subuncinate arm; 

 from the posterior side, near the apex of the gonopod, a trifurcate 

 process extends caudolaterad. Located behind the base of each 

 gonopod is an oblique oval structure with the inner or upper end 

 developed into a long and very slender cylindrical process reaching 

 the lateral arm of the gonopod. Base of the gonopods outwardly 

 protected by several thin, erect, shieldlike plates. 



Males with a comb of fine hairs on the under side of the last 

 joint of legs 1 and 2. Other legs in front of the gonopods, and 

 some succeeding legs, with a velutinous pad on the lower distal 

 half of the last joint. Females with a comb of hairs on legs 1 and 

 2, as in the males, and sometimes a comb on leg 3 also, but there 

 are no velutinous pads on the succeeding legs. Coxae of all legs 

 of both sexes normal, lacking produced lobes, although baglike 

 structures may at times be extruded from the coxae of some anterior 

 legs. 



