AMERICAN COMPONENTS OF THE TENTYRIIN^ 437 



remainder of the surface sparse and extremely minute. Length 

 7,6 mm.; width 3.2 mm. (?). Arizona gravidulus n. sp. 



Form more elongate, similar in coloration, the very minute hairs even 

 less obvious ; head very much narrower than the prothorax, punc- 

 tured finely and sparsely, with some feeble rugaj and acute juxta- 

 carnal folds as in the preceding species; prothorax large, more 

 transverse, nearly two-fifths wider than long, the sides unusually 

 convergent in about basal half, becoming straight and obliciue, 

 with the basal angles formed by the basal bead as usual, the 

 apical angles thickened and prominent, the punctures only moder- 

 ately small and less sparse than in the preceding species, becom- 

 ing coarse and separated by much less than their own widths 

 laterally; elytra elongate-oval, fully one-half longer than wide, 

 the base very strongly margined as usual but prolonged anteriorly 

 beyond the arcuate part of the sides, suggesting a broad basal 

 peduncle in a manner not noticeable in any of the preceding 

 species, the punctures of the series only moderately coarse, those 

 of the remainder of the surface minute but evident. Length 8.5 

 mm. ; width 3.2 mm. (?). Arizona (Riverside), — H. F. Wick- 

 ham basalis n. sp. 



Form nearly similar to basalis but smaller in size, similarly black and 

 glabrous; head and general form almost exactly similar in the 

 sexes, the former punctured and sometimes feebly rugulose as 

 usual ; prothorax about a third wider than long, the sides arcu- 

 ately and moderately converging in about basal half, the apical 

 angles thickened and somewhat prominent, the punctures sparser 

 than in basalis and separated laterally by their own widths or 

 more ; elytra nearly as in basalis in form and sculjjture but not 

 produced anteriorly at base. Male with the densely fulvo-pubes- 

 cent fovea of the basal segment of the abdomen feebly impressed 

 and but little elongated. Length 7.2-7.4 mm.; width 2.S-2.9 

 mm. (cJ* and ?). Arizona (Benson), — G. W. Dunn. 



histrio n. sp. 



13 — Body rather stout, strongly convex, black and rather strongly 

 shining throughout, glabrous; head much narrower than the pro- 

 thorax, minutely, sparsely punctured and smooth, with a single 

 strong acute plica near the carinte ; prothorax nearly two-fifths 

 wider than long, rather strongly and arcuately narrowed behind 

 from near apical third, the apical angles not -at all thickened or 

 prominent, the punctures only moderately small, impressed, 

 sparse, becoming moderately coarse, impressed and separated by 

 nearly twice their own witlths laterally ; elytra one-half longer 

 than wide, oval, the very feebly impressed series composed of 

 moderately coarse punctures, the remainder of the surface very 

 sparsely and minutely punctate, scarcely distinctly so even toward 

 base. Male with a nigro-pubescent abdominal fovea, much smaller 

 than in any of the preceding species, not impressed and elongate- 

 oval. Length 7.7 mm. ; width 3.2 mm. (d^). California (San 

 D iego ) gracilicornis n . sp . 



