H. C. FALL. 



103 



think, unquestionably representatives of the species he had 

 in hand. If so, the pale color as described by Say is normal 

 and not due to immaturity as LeConte believed, and the true 

 armatus is not at all the species accepted as such by that 

 author, and following him by all our later Coleopterists. In 

 genuine armatus the color is ordinarily pale yellow, the head, 

 abdominal apex and sutural bead black or blackish ; some- 

 times the prothorax and abdomen are of a darker shade than 

 the elytra, but are never black. In armatus as defined by 

 LeConte the body is black, the elytra varying from rufous 

 to piceous, the abdominal apex paler. In this the hind angles 

 of the prothorax are broadly rounded and undefined ; in 

 armatus they are distinct and slighty prominent. The arma- 

 tus of LeConte is a common species, widely dispersed over 

 the western United States, and naturally subjected to some 

 variation, but I am thus far unable to find in a quite exten- 

 sive material from different localities any satisfactory char- 

 acters for specific separation. One of these local races 

 served as the type for strenuus Csy., and this name should 

 now be used for the species. 



B. arizonensis n. sp. 



Rather slender, black, or piceous black, trochanters and tarsi dark 

 rufous, tibiae more or less rufopiceous. Antennas entirely black or 

 piceous, second joint a little stouter and longer than the third, the 

 latter twice as long as wide and subequal in length to the next two ; 

 outer joints gradually wider, 7-10 distinctly transverse. Head densely 

 finely granulato-reticulate, a few fine and feeble punctures posteriorly, 

 vertex with a feeble median tubercle divided by a short impressed line. 

 Prothorax a little wider than the head, a little wider than long, sides 

 parallel in apical two-thirds, then very broadly rounded into the base, 

 the lateral and basal angles completely undefined, apical angles right 

 but rather broadly rounded, surface granulato-reticulate and dull like 

 that of the head ; punctuation sparse, moderately coarse; median line 

 strongly impressed. Elytra at base a little wider than long, sides 

 nearly straight and evidently divergent, apical angles broadly rounded, 

 surface shining, rather closely but not coarsely punctate. Abdomen 

 finely reticulate and sparsely finely punctate above, more closely punc- 

 tate beneath, with very fine reticulato-rugulose ground sculpture. 

 Hvpomera vaguely concave posteriorly, not impressed along the outer 

 margin, the width at apex about half that at base, which is subequal 

 to the length of the coxal fissures, the latter almost completely closed. 

 Length 4.3-4.9 mm. 



TRANS. AM. ENT. SOC, XXXVI. MAY, 1910. 



