EEVISION OF LISTROCHELUS SAYLOR 71 



21 (20). Pygidium polished, finely punctate, nearly glabrous 



(except under high power) ; apex gibbose and slightly 

 overhanging itself in lateral view, apical margin with 

 two small and very obtuse teeth, separated by a broad 



and shallow emargination (fig. 4, c) meadei, new species 



Pygidium not exactly as above 22 



22 (21). Apex of fifth abdominal segment with a broad and moder- 



ately deep emargination; pygidial disk and dorsal 

 surface highly polished; larger tarsal tooth subapical in 



position cochisa, new species 



Apex of fifth abdominal segment entire, not at all emar- 



ginate 23 



23 (22). Larger teeth of front tarsal claws subapical in position; 



elytra densely pruinose 24 



Teeth of front tarsal claws always median in position or 



nearly so; pruinosity variable 25 



24 (23). Pygidium and thorax highly and entirely polished, not at 



all pruinose; inner hind tarsal claw^ usually with a larger 

 intercalated tooth (this frequently w-orn) (Arizona) . .plena (Fall) 

 Pygidium and thorax always pruinose, at least in part; 

 inner hind tarsal claw always without a larger tooth 

 (Texas) reinhardi, new species 



25 (23). Pygidium noticeably flattened and densely hairy, basal 



half pruinose, disk densely, coarsely, and rugosely 

 punctate, apex broadly rounded; elytra with moderately 



long to short, erect hairs (Arizona) trochanter, new name 



Pygidium variable, never as above 26 



26 (25). Base of clypeus noticeably tumid, pygidium flat to slightly 



convex, surface coarsely rugose, slightl}' polished and 

 with dense short hairs, apex with coarse spines, all claws 



subpectinate along a double row (Arizona) granti, new species 



Base of clypeus flat, pygidium convex, surface polished, 



pilosity absent or present 27 



27 (26). Thorax more than twice as wide as long, lateral margin 



behind median dilation straight or slightly sinuate; 

 center base of pygidium with slight but noticeable fovea 

 at point of juncture with propygidium; elytra always at 



least slightly pruinose 28 



Thorax scarcely twice as w'ide as long, lateral margins 

 straight or nearly so posteriorly; center base of pj'gi- 

 dium not impressed; elytra and dorsal surface shining 

 to slightly pruinose 31 



28 (27). Pygidium broadly rounded to semirounded apically, disk 



strongly convex; thoracic disk never with hair except at 

 sides; first hind tarsal segment frequently much wider 



at apex falsa (LeConte) 



Pygidial sides noticeably convergent apically, apex trun- 

 cate, usually markedly so; usually with at least some 

 hair on disk, at times this rubbed off 29 



29 (28). First front tarsal segment with a strong inner spine, width 



of segment at apex nearly one-half total length (fig. 3, n) ; 

 elytral area near suture with moderately dense, long, 

 erect hairs (New Mexico) koehleriana, new species 



