Coleopterological Notices, VI. 609 



«lighth' more tlian twice as long as wide. In one respect riversi 

 -diflers from all the other members of this genus, the female being 

 more densely and conspicuously clothed than the male ; it is pos- 

 sible, however, in spite of general facies, that this female does not 

 really belong to the same species, especially as the basal angles of 

 the prothorax are broadl}' rounded. The hairs are much finer 

 than usual. 



The two examples in my cabinet were kindly communicated by 

 Mr. J. J. Rivers, who possesses a considerable series. 



These species should ])oth be placed between carpenteri and 

 squamicollis in the table previously published by me (Col. Not. 

 I, p. 170). 



It is impossible to properly associate the males and females in 

 this genus unless the^- be collected at the same time and place, 

 and it is consequently seldom prudent to base a species upon the 

 female alone. 



XYLORYCTES Hope. 



X. failiillS 11. sp. — Moderately stout, strongly convex, polished, black 

 throughout above, dark red-brown beneath, the tibise and tarsi somewhat 

 pieeous in tinge; under surface clothed with long brownish-red hair, the upjjer 

 surface and pygidiiim glabrous. 



JTale — Head less than one-third as wide as the prothorax, the clypeal apex 

 retiexed and bilobed; dorsal horn nearly in satyrus but shorter. Prothorax 

 three-fourths wider than long, widest near the middle, the sides rounded, 

 strongly convergent, anteriorly; discal declivity beginning at the middle when 

 viewed from above, deep, somewhat excavated, it posterior margin prominent 

 but rounded in the middle, its surface covered sparselj- with transversely sub- 

 crescentiform punctures, the posterior elevated surface coarsely and densely 

 punctured anteriorly at the sides. Elytra nearly as long as wide, equal in 

 width to the prothorax and twice as long, obsoletely striato-punctate. Pygid- 

 ium two and one-half times as wide as long. 



Female — Scarcely at all narrower than the male, the head nearly as in saiy- 

 rus. Prothorax two-thirds wider than long, evenly convex but feebly im- 

 pressed and more densely and roughly punctured near each apical angle; sides 

 evenly convergent and broadly arcuate from near the base, the basal angles 

 broadly rounded. Elytra very nearly as long as wide, more deeply striate than 

 in the male, the pygidium more canaliculate along the lower margin. 



Length 28.0-30.0 mm.; width 15.0 mm. 



Arizona. 



This species differs from satt/7'us in its narrower and more 

 elongate form. The male differs from the corresponding sex of 

 satyrus in having the A^ertical wall of the thoracic depression 



