Monographie der Bienengattung Centris (s. lat.). 2gD 



blackish-brown hairs. Pvgidium rufescent at base, narrow at end, longitudinally sulcate 

 on each side. Long. 15 — 18 mm. 



»cT. Eves olive-green; clvpeus and labrum bright lemon-yellow; scape wholly 

 dark; mandibles dark reddish brown, with black tips; claw-joints rufous; legs with more 

 pale pubescence; bind femora broad, the pubescence without pale, except at end. Apex 

 of abdomen with pale hairs. Long. 16 mm.« 



Centris caesalpiniae liegt mir in einem typischen g vom Autor vor; ich finde 

 keinen fassbaren Unterschied von hnffrnanseggiae\ (vgl. Anhang). 



80. Centris hoffmanseggiae Cockll. 



1897. Centris hoffmanseggiae Cockerell, cf $ , Ann. and Mag. Nat. Hist. (6), XIX, 

 pag. 395. 



»d". Black, with white pubescence, that on thorax above tinged with ochraceous. 

 Eves greyish, front narrow, hardly as broad as an eye, scape wholly black; clypeus, a 

 line above transversely, labrum, and basal portion of mandibles yellowish white. Man- 

 dibles rufous at the junction of the white with the black ends; a strong inner denticle. 

 Clvpeus bare, with sparse shallow punctures. Pubescence of thorax dense. Tegulae 

 reddish testaceous. Wings hvaline, nervures and stigma piceous. Third submarginal 

 narrowed about one half to marginal. A dark shade looking like a stump of a nervure 

 at lower outer corner of third submarginal. Pubescence of legs wholly pale, bind legs 

 not dilated, the white hairs long on outer side, but not forming a broad dense mat, as 

 in other species. Claw-joints and basal half of claws rufous. Claws deeply bifid. Ab- 

 domen with Short greyish-white pubescence, tolerably dense on first two segments, 

 sparse on the others, giving way to fuscous on 4 and 5, but the bind margins with 

 narrow thin white hair-bands. Apex with white hairs. Long. 12 mm. 



»5. Verv much like the female of caesalpiniae, with the same broad black brush 

 of hairs on the bind legs, the same black abdomen etc. The thoracic pubescence ave- 

 rages paler than in caesalpiniae. Eyes grey. Clypeus and labrum dull orange-yellow, 

 the Upper corners of the clypeus more or less black, frequently the whole upper margin 

 of the clvpeus broadly black. Scape wholly black. Mandibles rufous, with black ends 

 and base. Pubescence of abdomen very sparse and black, first segment sometimes with 

 pale pubescence, but never the second. Claws small, w'ixh a little tooth within. Wings 

 smokv hyaline. Front broad, inner orbits parallel. Long. 12 —14 mm. 



»Hab. College Farm, Mesilla Valley, N. M., at flowers of Caesalpinia falcaria, 

 May 18, 1896, I cf, 7 9. 



»I had at various times swept over the flowers of Caesalpinia (hoffmanseggia) 

 falcaria var. stricta (Benth.), without getting any bees, and had wondered why this 

 was. But on May 18 I observed that they were indeed visited by bees of the genus 

 Centris, which were much too agile to be caught by sweeping. The C. caesalpiniae, 

 in its typical female, was especially hard to catch, hovering over the flowers with a 

 curious swinging motion, darting away at the least alarm. It was interesting to find 

 several species of Centris, a neotropical genus with only one hitherto recorded U. S. 

 species, at flowers of Caesalpinia, a typically tropical genus of plants. 



»When I came to arrange all the specimens of Centris caugth in the Mesilla 

 Valley, I found I had four ditferent males and four different females, presumably be- 

 longing to one another. The females are much ahke, but the males present wider diffe- 

 rences; and while 1 think I have the sexes properly associated, it must be admitted that 



