REVISION OF LISTROCHELUS SAYLOR 81 



highly polished and evenly convex at middle, with fine and sparse 

 setigerous punctures, the sixth and apical portion of the preceding 

 segment slightly more coarsely punctate. All claws except the inner 

 hind one with a sharp median tooth intercalated with the serrations, 

 which occur in a double row; hind inner claw serrate but without the 

 larger intermixed tooth. Hind tarsus only slightly pilose below. 

 Otherwise similar to male. 



Length. — 13-17. 5 mm. Width. — 5. 5-9 mm. 



Type. — In the LeConte collection. 



Type locality. — "Sonora, near the Boundary line." 



Specimens examined — Males 97; females, 63. Arizona: The range 

 is rather general over the southern half of the State south of Prescott. 

 June 6 (Sabino Canyon) to middle August (Buckeye). Taken on 

 Olneya tesota (desert ironwood) by Ernest Holt at Higley. 



Remarks. — This very distinct and common species can be dis- 

 tinguished in either sex probably more easily than any other of the 

 group; the unusual abdominal armature and hairy hind tarsi of the 

 male, as well as the pygidial characters of the female, are unique in 

 the United States fauna. The male in abdominal armature is closely 

 related only to the Mexican species L. terminalis Saylor and L. gentryi 

 Saylor. 



PHYLLOPHAGA (LISTROCHELUS) DISPARILIS (Horn) 



Figures 1; 6, a-d; 8, m 



Ldstrochelus disparilis Horn, Trans. Amer. Ent. Soc, vol. 7, p. 141, 1878. 



Male. — Elongate, subparallel, rufocastaneous, shining above, with 

 or without faint pruinose markings on elytra. Head with transverse 

 carina strong; front flat, densely, coarsely, and not confluently punc- 

 tate, glabrous; clypeal suture fine, subarcuate, not impressed; clypeus 

 punctured as front but much more densely so at center of disk; 

 apex of clypeus subtruncate, angles moderately rounded, the margins 

 slightly reflexed; clypeus as long as the front. Labrum very deeply, 

 widely, semicircularly emarginate. Antenna 10-segmented, club 

 small and slightly longer than funicle. Thorax broad, moderately 

 densely, finely, irregularly punctured, more closely so at sides, disk 

 glabrous; base and apex with strong marginal lines, lateral margins 

 ciliate and coarsely crenate ; hind angles nearly rectangular, front angles 

 slightly obtuse but distinctly angulate. Elytra punctured as thorax 

 but less densely so, first and second striae weakly indicated, sutural 

 striae strong; surface of elytra with sparse, short, suberect hairs; 

 lateral margin with long cilia. Pygidium strongly convex, higlily 

 polished, very finely, moderately densely punctate, with very short 

 suberect hairs; apex truncate and broad. Abdomen very shallowly, 

 widely, and longitudinally channeled at center, surface moderately 



