342 H. Friese. 



9. Centris atriventris Fox. 



1899. Centris atriventris Fox, cf 9, Natural sc. Philadelphia, pag. 68. 



9. Black; head in front and cheeks with grayish pubescence, that on vertex pale 

 fulvous; clvpeus yellow, broader than long, strongly punctured but smooth down 

 middle; labrum yellow, semilunate, strongly punctured, its apex broadly and roundly 

 slightly emarginate; flagellum testaceous beneath from apex of first Joint, the latter 

 distinctlv shorter than the four following joints; scape entirely dark; thorax above with 

 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 fuscous 

 brown, with that on tarsi black; on the other legs it is black, except on the medial tibiae 

 outwardly, where it is rather similar to that of the fore legs; abdomen shining black, 

 the first segment anteriorly with pale pubescence; the apex of first and the second to 

 fourth dorsal segments quite nude; the apex of fifth dorsal fringed with dark hairs; 

 second to fourth ventrals fringed apically and clothed medially with long black hairs; 

 sixth segment with black hairs, the pygidium triangulär, with a triangulär raised area 

 at base which sends out a carina from its apex which reaches nearly to tip of pygidium; 

 wings subhyaline. Length 12 mm. 



cT. Similar to 9 in coloration, but with the mandibles within toward the base, 

 the inner orbits as high as Insertion of antennae and a line on scape, yellow; first Joint 

 of flagellum not as long as two following united; labrum semicircular, not emarginate; 

 dark pubescence of ventral surface of thorax not so evident as in the 9. Length 12 mm. 



Texas. One female and two male specimens. A female specimen from lower 

 California agrees in coloration with this species, but there is a slight difference in the 

 shape of pygidium. I am not quite certain that it is the same, however, as the first ab- 

 dominal segment is scarcely pubescent. 



10. Centris lanosa Cress. 



1872. Centris lanosa Cresson, cf, Trans. Am. Ent. Soc, pag. 284. 



1897. Centris lanosa Cockerell, cT, Trans. Am. Ent. Soc, pag. 897 (non 9). 



Texas; New Mexico: Las Gruces. The pale patch at base of hinjd tibiae externally 

 is characteristic of this species. The pubescence of femora varies from brown to pale. 



1 1. Centris subhyalina Fox. 



1899. Centris subhyalina Fox, 9. Natural sc. Philadelphia, pag. 69. 



9. Black, including clypeus and labrum; head in front and on cheeks with grayish 

 pubescence, that on vertex pale fulvous; clypeus strongly punctured, with a raised 

 smooth line down centre, the fore margin narrowly reddish-testaceous; labrum semi- 

 circular, strongly punctured, its outer margin narrowly reddish-testaceous; flagellum 

 obscurely testaceous beneath from apex of second Joint, the latter a little longer than 

 the following three Joints united; scape not pale; thorax with pale fulvous pubescence 

 above extending half way on sides, where it is met by black-brown pubescence which 

 clothes the under surface; pubescence of middle segment and first segment of abdomen 

 paler, legs dark red, or black, the pubescence of four posteriors entirely black, that of 

 the anteriors brownish; abdomen shining black, the apex of first, and the second to 

 fourth dorsals bare; fifth dorsal as well as the second to fifth ventrals fringed with black 



