REVISION OF LISTROCHELUS — SAYLOR 115 



PHYLLOPHAGA (USTROCHELUS) SENEX (Horn) 



Figure, 2, b 



Listrochelus senex Horn, Trans. Amer. Ent. Soc, vol. 7, p. 148, 1878. 



Male. — Oblong-oval, rufous and shining above, glabrous dorsally. 

 Head without an obvious transverse carina on vertex, front very 

 densely, coarsely, and variolately punctate; clypeal suture nearly 

 straight; clypeus flat, more sparsely punctate than front; clypeal apex 

 hardly at all reflexed, subtruncate, the center faintly emarginate, 

 angles narrowly rounded. Antenna with club ver}'^ robust (thickest 

 in subgenus) and slightly longer than to one-third longer than, the 

 funicle; segments 4-7 inclusive somewhat, to distinctly, transverse. 

 Thorax very convex, with sparse coarse punctures in center disk, the 

 punctures closer laterally; lateral margins coarsely crenate, front 

 angles blunt, hind angles sharp but obtuse, base with a strong margi- 

 nal line. Elytra sparsely and not very coarsely punctate, striae obso- 

 lete. Pygidimn somewhat convex, smooth and shining, with very 

 small punctures and very short and sparse hair, apex rounded. Abdo- 

 men polished, smooth, very sparsely and finely punctate; sixth seg- 

 ment nearly as long as the fifth and with a short backward-projecting 

 lobe at center in lateral view (fig. 2, 6), the apex of the lobe truncate, 

 surface of the segment polished, smooth, sparsely and finely punctate. 

 All claws long and slender, minutely serrate along a single margin, 

 without any larger intercalated teeth. 



Female. — Black or rufous in color; transverse ridge of occiput rather 

 prominent; antennal club shorter than funicle; sixth abdominal seg- 

 ment plane, sparsely and coarsely punctate; pygidium slightly more 

 coarsely punctate than in the male; all claws finely serrate along a 

 single margin and each with a triangular tooth at center. Otherwise 

 as in the male. 



Length. — 11-12.5 mm. WidUt. — 5-6 mm.. 



Type. — In the Horn collection. 



Type locality. — "Llano Estacado, Texas." 



Specimens examined. — Males, 14; females, 3. Texas: Fort Clark 

 [Saylorj. New Mexico: Mesilla Park [U.S.N.M. and Saylorj; 

 Albuquerque, May 22 (Schaeffer) [Robinson, U.S.N.M., Caseyl. 



Remarks. — The color varies from rufous to or nearly quite black. 

 Apparently rather rare in collections. 



