THYCE AND POLYPHYLLA 339 



as long as wide, those of the rather ragged vittae and suture somewhat 

 smaller, dense and white; pygidium transversely arcuately triangular, 

 only feebly convex, the small stout and closely appressed fusiform 

 scales very close-set, sparser laterally; abdomen closely clothed with 

 appressed white scales throughout; tarsi slender, the intermediate 

 rather longer than the tibiae; anterior tibiae with the two apical 

 teeth long and acute, the outer edge also with a very short and acute 

 though vestigial tooth, just beyond the middle of the length. Length 

 23.5 mm.; width 10.3 mm. Utah (Prove), Spalding. One ex- 

 ample arguta n. sp. 



Pygidium with a very dense mixture of slender attenuate yellowish and 

 not so closely appressed squamules and very short fine hairs, vir- 

 tually throughout the surface; anterior tibiae purely bidentate as 

 usual; clypeus broader 21 



21 Form moderately stout, cylindric-oval, rather shining, pale rufo- 

 castaneous in color almost throughout, the abdomen black, the legs 

 ferruginous; head rather broad; vertex black, strongly punctured, 

 with many rather long erect coarse brown hairs and with decumbent 

 whitish scales near the eyes; clypeus rufous, moderately concave, 

 broad and arcuate at apex, the angles obtuse and blunt though 

 evident, the sides thence to the base slightly converging, the scales 

 attenuated, rather close-set, becoming smaller and dense laterally 

 and apically; antennae pale ferruginous, the club barely more than 

 twice as long as the stem; palpi slender, testaceous; prothorax short, 

 distinctly more than twice as wide as long, the margins strongly 

 crenulate basally, broadly rounded and subprominent near the 

 middle, thence equally converging to apex and base, feebly arcuate 

 in the former, straight in the latter, sense; punctures moderate and 

 sparse, the interspaces very shining; sparse yellowish scales large, 

 very long, lanceolate, all decumbent and none pubiform, the surface 

 completely without erect hairs, except at apex medially, where 

 there are some distinct coarse erect hairs; median line and oblique 

 sublateral vitta present in basal half only composed of large, more 

 whitish and very dense lanceolate scales; scutellum with a parallel 

 medial vitta of dense white scales, elsewhere broadly glabrous; 

 elytra barely two-fifths longer than wide, fully two-fifths wider than 

 the prothorax, rounding apically from slightly behind the middle, 

 shining, barely at all rugulose, virtually smooth, with fine sparse 

 punctures bearing long and gradually finely attenuate pale yellow 

 scales, about four times as long as wide, the ragged dense vittae 

 and suture white; pygidium wider than long, triangular, feebly 

 convex, the dense yellowish vestiture sparser narrowly along the 

 median line centrally and also in a small area near each side ; abdomen 

 with close-set whitish scales, which become gradually denser toward 

 the segmental apices; middle tarsi as long as the tibiae. Length 24.5 

 mm.; width n.o mm. California (El Dorado Co.). A single 

 specimen sobrina n. sp. 



Form much stouter and of rather larger size, the integuments and ves- 

 titure similar in coloration, the elytral surface much more rugose 

 and less shining; head unusually broad; vertex black, with strong 



