AMERICAN COMPONENTS OF THE TENTYRIIN^ 489 



than the head, widest anteriorly, where the sides are evenly 

 rounded, thence moderately converging and sinuate posteriorly, 

 becoming parallel in basal fourth, the sides and the truncate apex 

 and base densely fringed with short pale squamules, convex, 

 coarsely, densely punctate, with the scattered squamules closer 

 near the median line toward base, the surface narrowly and moder- 

 ately impressed along the median line, except anteriorly ; elytra 

 barely twice as long as wide and not quite twice as wide as the 

 prothorax, the sides rather gradually rounding toward base and 

 still more gradually and straighter toward the bluntly rounded 

 apex, parallel and almost straight, the yellowish squamules of the 

 ridges small, the marginal series confined to apical third or fourth ; 

 surface moderately convex, the punctures of the regular double 

 series coarse as usual, rather close-set ; abdomen smooth, some- 

 what coai-sely and not very sparsely punctate. Length 3.7-4.3 

 mm.; width 0.85-1.2 mm. Arizona (Tu9Son) regularis Horn 



Form rather slender, moderately convex, piceous or blackish, rather 

 dull in lustre ; head moderately large, evidently longer than wide, 

 the sides from the antennae to behind the eyes moderately con- 

 verging and nearly straight, then broadly, evenly rounding and 

 converging to the neck, the surface rather closely punctate and 

 with the usual scattered yellow squamules, the occiput very feebly 

 impressed at base; eyes above narrow, of about 19-30 facets, be- 

 neath of 5 facets ; prothorax distinctly narrower and shorter than 

 the head, distinctly elongated, widest and naiTowly rounded at the 

 sides anteriorly, thence very inoderately, subsinuously narrowed 

 to the base, fimbriate about the entire contour, the lateral hairs 

 shorter and thinner than those at the truncate ends ; surface con- 

 vex, even, not very densely punctate, with subevenly scattered 

 squamules, feebly impressed medially toward base ; elytra rather 

 more than twice as long as wide and fully twice as wide as the 

 prothorax, the flavate squamules along the ridges and the double 

 series of coarse punctures nearly as in regtilaris^ the punctures 

 less close-set in the series as a rule ; abdomen similarly punctate, 

 the propleurae very sparsely. Length 3.8-3.9 mm.; width i.o 

 mm. Texas (El Paso) \ simplex Csy. 



13 — Body moderately slender and convex, somewhat as in regularise 

 opaque anteriorly, densely punctured and blackish-castaneous, the 

 elytra more shining and rufescent as usual ; head but little longer 

 than wide, parallel and somewhat arcuate at the sides to the broadly 

 rounded basal angles, the base broad, the occiput not impressed; 

 eyes broadly divided as usual, the upper part long and narrow, 

 the lower minute ; scattered squamules short but broad ; prothorax 

 larger than usual, evidently shorter but only slightly narrower than 

 the head, widest behind apical third, where the sides are sub- 

 prominently rounded, thence moderately converging and nearly 

 straight to the base, having a dense short fringe of coarse squam- 

 ules throughout the contour, the surface convex, flattened narrowly 

 along the middle and evidently impressed near the base, where 

 Proc. Wash. Acad. Sci., October, 1907. 



