396 BULLETIN 03, UNITED STATES NATIONAL MUSEUM. 



of the dorsal plate, finely and densely setnlose. Fossa largely yisible 

 from aboye and rather capacious, margins with a feAv scattered seta\ 



Afpendage moderate in size, mammilliform and penicillate, seta^ 

 quite long, two or three extending beyond apex. 



Baikal proTninences slightly eyident. 



Superior pudendal membrane longitudinally rugulose, rather 

 broadly exposed and attaining the apical fourth of the dorsal plate. 



Ventrolateral sarfaces (Plate l,fig. :2) not swollen, surface flattened 

 centrally to base and convex laterally. Apex concave beneath. vSub- 

 marginal groove shallow and passing into a broad lateral and apical 

 concavity; surface not noticeably setose; internal margins setulose at 

 ajDex. Internal margins of the valves contiguous in basal half, the 

 genital fissure in apical half, very narrow and nearly closed. 



Ilahitat. — Oregon; "Washington (Pullman, May, C. V. Piper); 

 Northern California (Modoc County) ; Nevada (Verdi, April, abun- 

 dant) ; Arizona (Williams, June, Barber and Schwarz; Humphrey's 

 Peak at the base, F. H. Snow) ; Colorado (mountains southwest of 

 Montrose; Durango; South Park; San Luis Valley; Ouray; Veta 

 Pass, 9,200 feet; Buena Vista; Colorado Springs; Florissant; Gar- 

 land; Idaho Springs; Georgetown; near Long's Peak; Fort Collins, 

 Wickham's List. South Park, elevation 8-10,000 feet, August, 

 Golden, Dyar and Caudell; Chenney Gulch); NeSv Mexico (Santa 

 Fe, LeConte) ; Nebraska (Black Hills, LeConte; Sioux County, Coll. 

 Univ. Nebraska) ; Idaho; Western Kansas; Dakota. 



Number of specimens studied, 350. 



Type in the LeConte collection. 

 ' Type-locality. — Black Hills, Nebraska. 



Salient type-eliaracters. — Elongate, subopaque. Thorax subquad- 

 rate, narrowed behind, sides broadly rounded, apex almost tnmcate, 

 moderately convex, sharply and rather densely punctate. Elytra 

 declivous behind and obliquely narrowed, irregularly punctate, punc- 

 tures especially at the sides muricate and very briefly setiferous. 

 Legs muricato-punctate; anterior femora obtusely sinuate (LeConte). 



Diagnostic characters. — Nigrina by its suboi)aque integuments and 

 more or less muricate sculpturing differs from all the other species 

 of the subgenus MetaMapylis. 



In the race perlonga the body surface is very bright and shining. 



In dissimilis the form is more ovate, usually less elongate and more 

 depressed ; the elytra are smoothly sculptured and the stria3 more 

 evident and distant. 



Schwarzii more robust and the form is more like some Asida\ as 

 conrexa^ the pronotum is less convex, more transverse, more dilated 

 at the sides, so that the margin is distinct and prominent. 



Nevadensis is uiucli more slender in every way, more or less aluta- 

 ceous and opaque. 



