382 PROCEEDINGS OF NATIONAL MUSEUM vol. 99 



marginal ridges; keels extending caudad of median posterior portion 

 of tergites. Segments 14 to 19 with posterior lobes equal in length 

 to tergites at midline. All tergites comparatively flat and smooth. 

 Repiignatorial pores lateral in position, in some cases directed slightly 

 downward. 



Anal segment triangular in dorsal aspect, longer than broad, its 

 basal width less than distance between keels of penultimate segment ; 

 truncate distally. Anal valves inflated, glabrous, with many small 

 ridges and grooves on cephaloventral portion of each. Preanal scale 

 roughly triangular with very large terminal lobe. Mesial ridges of 

 anal valves unusually large. 



Bases of last pair of legs very close. Legs of segments 8 to 18 similar, 

 sternites of posterior pair of legs on the segments with conspicuous 

 processes; coxae and trochanters unarmed, femoral spines large. 

 Distal tai'sal joint shorter than basal two, shorter than femur. Coxae 

 of second pair of legs of male with cylindrical processes, rounded dis- 

 tally. Males with sternites between fourth legs with high conical 

 knobs. Pregenital legs much more hirsute than postgenital limbs, 

 and with heavy, blunt claws. 



Gonopods at rest lie parallel and directed cephalad, reaching to 

 the sternites of the fifth pair of legs, the terminal branches of the 

 lateral processes crossed. Telopodite composed of two elements: a 

 small bladelike mesial process which projects distad from the mesial 

 side of the lateral process to the level of the terminal branch of the 

 latter. Lateral process an almost straight cylindrical shaft with a 

 terminal, distally directed tooth and a large subterminal branch which 

 is bent mesiad and cephalad. Base of telopodite with the usual lateral 

 setiferous shoulder and other structures as shown in the drawings. 



In life, tergites blackish (occasionally dark olive-gray with a median 

 dark line), the keels red on both corners as well as margin; extreme 

 edges of keels colorless; underparts of body whitish gray. Head 

 black on top, brown in front with edges of labrum a lighter brown ; 

 antennae light brown with distal portion of each article white. 



Type iipecimenH. — Male holotype in the U. S. National Museum, 

 No. 1784. Several topoparatypes in my personal collection, RLH Nos. 

 4-2747-1, 5-1847-lc, and 6-147-la. 



TyiJc locality. — McGraws Gap, 3 miles northwest of Clifton Forge, 

 Alleghany County, Va. A deep watergap in sandstone ridges, with 

 the forest composed chiefly of Tsuga canadensis.^ Liriodendron tulip- 

 ifem., Quercus alha., Q. pTinus., Acer rubnim, A. penrtsylvanicum.. 

 Rhododendron maxiinmn, and Kalmia latifolia. Herbaceous plants 

 at the type locality include Urtica dioica, Mitella diphyUa, Mitchella 

 repens^ and the ferns Poly podium virginianum and Polysiickum 

 acrostichoides. 



