386 PROCEEDINGS OF NATIONAL MUSEUM vol.98 



Nannaria simpJex appears to be quite scarce. Despite many fre- 

 quent searches at the type locality (which have produced many speci- 

 mens of erlcacea) only the holotype has been found. It was dis- 

 covered under a small bit of hemlock bark, and when uncovered ran 

 off with some show of celerity. 



NANNARIA WILSONI, new species 

 Plate 27, Figures 15, 16 



Diagnosis. — A medium-sized member of the genus, characterized 

 by the male gonopods, which are deeply bifurcated with the lateral 

 process larger, the distal portion becoming flattened and twisted on 

 its axis. Mesial process smaller, a simple spiniform branch. 



Description. — Length of holotype, 25, width, 5 mm. Body width 

 averages 20 percent of length. Segments between second and fifteenth 

 of full width, body abruptly rounded in front, gently tapering be- 

 hind. 



Collum large, subtrapezoidal in dorsal aspect, sides straight and 

 with very small marginal ridges; front slightly convex. Posterior 

 edge emarginate across body ; posterior corners angular. Collum as 

 long as succeeding two segments combined. 



Keels of segments anterior to fourteenth shorter than tergites at 

 midline; posterior edges of keels tapering cephalad; lateral edges 

 with well-developed marginal ridges. Segments 3 through 13 sub- 

 similar, anterior corners almost square, posterior corners directed 

 slightly caudad. Segments 14 through 19 with keels becoming in- 

 creasingly produced caudally, those of 19 with posterior lobes large 

 and bluntly rounded. All tergites comparatively flat, and very 

 smooth. Eepugnatorial pores lateral in position, in some instances 

 directed slightly downward. 



Anal segments triangular in dorsal aspect, as long as broad, its 

 basal width less than distance between keels of penultimate segment, 

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

 and grooves on the cephaloventral portion, mesial ridges very large. 

 Preanal scale triangular, more pointed than in simplex. 



Bases of last pair of legs relatively close. Legs of segments 8 

 to 18 subsimilar; sternites of posterior pair of legs of each segment 

 with conspicuous spines; coxae and trochanters unarmed, femoral 

 spines large. Distal tarsal joint longer than basal two, and as long as 

 femur. Coxae of second pair of legs of males with cylindrical, dis- 

 tally truncate processes. Sternites of fourth pair of legs of males 

 with conical processes which are ovoid in cross-section. Pregenital 

 legs much more hirsute than postgenital limbs, and terminating with 

 heavy blunt claws. 



