68 PROCEEDINGS OF THE ACADEMY OF [1899. 



specie?, a specimen received from Mr. Cockerell, marked "C. 

 cce--^alpini(e d^f" differing so obviously from the description that I 

 have conckided that it was so kabelled by mistake, and have de- 

 scribed it as new (see C. mary hiatus). 



6. Centris rhodopus Ckll. 



Centris ccesalpinm\&r. rhodopus Cockerell, Ibid., 395, ? cJ', 1^97. 

 New Mexico : Las Cruces. It seems better to regard this as a 

 distinct species from C. ccesalpinue ; it has well-marked differences. 

 One male, sent by Mr. Cockerell, has the abdominal hair- bands 

 more distinct and regular, and the pubescence of first hind tarsal 

 joint, instead of being entirely dark, is about evenly divided be- 

 tween dark-brown and whitish. 



7. Centris Hoffmannseggiae Ckll. 



Centris Hoffmaimseggice Cockerell, Ibid., 395, rf (uoii ?), 1897. 



Centris lanosa Cockerell (not Cresson). Ibid., 397, $ (non cT), 1897. 

 New Mexico : Mesilla Vcilley. To my mind Mr. Cockerell has 

 confused the sexes of Hoffmannseggiae and lanosa, judging from his 

 descriptions. Cotypes of Hoffmannseggice 9 differ at once from 

 the described male in their bare abdomen beyond the first segment, 

 the d" having the abdomen pubescent on all the segments, es2:)ecia]ly 

 the two first. Now, the ? lanosa described by Cockerell, has 

 " the second abdominal segment, as well as the first, delicately 

 pruinose." In the male lanosa the first segment only is pruinose. 



8. Centris Cockerellii n. n. 



Centris Hoffmannseggice Cockerell, Ibid., 395, 9 (non (^), 1897. 

 New Mexico: Mesilla Valley. I propose this name for the species 

 described as the female of Hoffmannseggice, which is apparently 

 distinct from the latter. 



9. Centris atriventris n. sp. 



?. — Black; head in front and cheeks with grayish pubescence, 

 that on vertex pale fulvous; clypeus yellow, broader than long, 

 strongly punctux'ed but smooth down middle ; labrum yellow, semi- 

 lunate, strongly punctured, its apex broadly and roundly slightly 

 emarginate ; flagellum testaceous beneath from apex of first joint, 

 the latter distinctly shorter than the four following joints; scape 

 entirely dark ; thorax above Avith pale fulvous pubescence, that on 

 sides slightly paler, beneath the pubescence is black, or blackish - 

 brown; legs reddish-brown, the pubescence of the anterior ones 



