H. C. FALL 333 



•quillett); Inyo Mts., 7,000-9,000 feet (Wickham). Arizona: two pxamjjles 

 without definite locality referred here with some doubt. 



In color desertus resembles xanti quite closely, but the latter 

 is more robust, thorax more conical in form, elytral intervals 

 wider with more numerous interstitial punctures. Its affinity 

 with analis is, however, more marked as indicated aljove, and, as 

 in analis, there exists an unusual instability in the degree of 

 separation of the eyes, which as a rule are rather closer in the 

 present species. 



10. Pachybrachys xanti Crotrh 



Very robust, rufo-testaceous, prothorax unusually long, sub- 

 conical with smooth median line, with or without faint darker 

 shades; metasternum more or less infuscate; pubescence short, 

 sparse, inclined. Average length 4.3 mm. Texas to Utah and 

 Southern California. 



Head rather closely evenl}- punctate, frontal spots vague to fairly distinct, 

 .surface shining, scarcely visibly alutaceous. Eyes separated in the male by 

 twice the length of the basal antennal joint or slightly more, in the female by 

 three times the length of the basal joint, or by about the length of the basal 

 four joints. Antennae extending a little beyond the humeri in the male, 

 scarcely attaining the hind angles of the thoi-ax in the female, pale throughout, 

 or with the outer joints dusk}'. 



Prothorax unusually long, subconical, widest at base, sides nearly straight 

 or but slightly curved, usually perceptibly sinuate before the hind angles; 

 surface polished, denselj- nearly evenly punctate with very narrow entire or 

 subentire smooth median line; punctures not very coarse, of nearly equal size, 

 less dense along the side margins, minute interstitial punctures nearly wanting. 



Elytra a little wider than the prothorax, very little longer than wide, obviously 

 narrowed from the humeri to the apex; surface finely alutaceous, dull, coarser 

 punctures forming fairly regular but not or but feebly impressed series; inter- 

 vals wide, rather densely confusedly punctate, these latter punctures nearly 

 as coarse on the disk as those of the strial series. 



Beneath body punctured and pubescent as usual; legs rather stout; front 

 claws of male not enlarged. 



Length 3.5 to 4.8 mm.; width 2.2 to 2.8 mm. 



Distribution. — Lower California: type, collected by Xantus. California: 

 Jacumba, San Diego Co., July 1 (Field). Arizona: Bill Williams Fork and 

 "Cactus Plain" (Snow); Phoenix, feeding on Atriplex, June 8, (H. B. Shaw); 

 Hot Springs, June 27 (Barber & Schwarz) ; "Ari" numerous collections. Utah: 

 St. George, July (Wickham). Texas: El Paso (Wickham; Barber and Schwarz) . 



11. Pachybrachys marmoratus Jacoby 



Very similar to xanti in nearly all respects, the differences being as follows: 

 Size a trifle smaller on the average, with the form rather less robust; color pale 



TRANS. AM. EXT. SOC, XLI. 



