REVISION OF LISTROCHELUS — SAYLOR 87 



Male. — Robust-oval, shining nifocastaneous, usually uith pruinose 

 patches on sides of thorax, basal part of pygidiuni and on the elytra 

 to a greater or lesser extent (rarely elytra entirely pruinose and thorax 

 nearly so); sparsel}^ haiiy on elytra, especially in basal part, rarely 

 glabrous. Head \vitli a very strong transverse carina, front very 

 densely coarsely punctate; clypeus less densely and less coarsely 

 punctured than front, middle of disk very sparsely so; apex sub- 

 truncately rounded, very strongly reflexed, angles strongly rounded. 

 Antenna 10-segmented, club slightly longer than funicle. Thorax 

 moderately densely, somewhat coarsely punctate, the punctures more 

 sparse at center of disk and very dense near front margin; disk ap- 

 parently glabrous; lateral margins crenulate, with long ciha; front 

 angles subrounded, hind angles subangulate but very obtuse; front and 

 hind margins strongly margmed, the latter mth long erect cUia. 

 Elytra finely, somewhat rugosely punctate, with very fine sparse 

 hairs, the latter often rather dense near base and scutellum; striae 

 including sutural hardly obvious. Pygidium strongly convex, finely 

 and densely punctured, with short suberect hair, the punctures much 

 sparser in apical third. Abdomen highly polished at middle and 

 flattened, very finely sparsely punctate, the sutures between the seg- 

 ments nearly punctate, with moderately long suberect hair. Hind 

 tibia with longest spur spatulate at apex ; first two tarsal segments 

 subequal in length. All claws pectinate along a double margin; 

 outer front claw with a large subapical tooth. 



Female. — Antenna! club equal to funicle. Pygidium densely 

 pruinose and semiconvex in basal half, polished and flat in apical 

 portion; the latter with a strong longitudinal impression at the 

 middle; disk with fine, not dense, setigerous punctures, the hair short 

 and suberect; apex subtruncate. Abdomen highly polished and con- 

 vex at the middle, with fine and dense pimctures, the hairs very short; 

 fifth sternite gibbose slightly beyond the middle; sixth shorter than 

 preceding and with dense, coarse, setigerous punctures. All claws, 

 except hind inner one, serrate to subpectinate along a single margin 

 (rarely with traces of a second margin), with a much larger tooth 

 beyond the middle of each claw; the hind inner claw apparently 

 serrate along a double margin and without a larger intercalated tooth. 

 Hind spurs strongly spatulate. Otherwise similar to the male. 



Length. — 12.5-19 mm. Width. — 5.5-9.5 mm. 



Type. — In the LeConte collection. 



Type locality. — "Fort Yuma, Colorado River, California" and 

 "Eagle Pass, Texas" for L. mucoreus; "Texas" for L. texanus; and 

 "Kansas, near Piatt River" for L. obtusus. 



Specimens examined. — Males, 91; females, 39. Texas: General 

 along the southwestern boundary of the State and apparently com- 



