374 HYMENOPTERA. 



thinly covered with fulvous pubescence, beneath thickly covered 

 with pale fulvous jjubescence. 



Hah. Brazil (Ega). 



25. Centris difformis. B.M. 



Female. Length 9 lines. — Head and thorax black, the fla- 

 gellum beyond the third joint fulvous beneath ; the cl3^peus 

 short, transverse and elevated, its anterior portion vertical, having 

 a transverse pale testaceous depression ; the labrum pale testa- 

 ceous, having two longitudinal fuscous stripes ; the mandibles 

 large, very broad at their base, and armed above with a stout 

 tooth, their apex bidentate, having a longitudinal pale testaceous 

 stripe; the cheeks densely clothed with white pubescence ; be- 

 tween the antennai and on each side of the face below their 

 insertion, a little white pubescence, that on the vertex black. 

 Thorax clothed with fuscous pubescence at the sides, beneath 

 it is cinereous ; the legs dark rufo-testaceous, the posterior pair 

 ferruginous ; the tibiae and basal joint of the tarsi densely clothed 

 exteriorly with bright fulvous pubescence ; the anterior and in- 

 termediate tarsi have a fulvous pubescence ; the wings smoky. 

 Abdomen ferruginous, the base having a little cinereous pubes- 

 cence, that at the apex ferruginous. 



Hah. Brazil (Rio Tapajos). 



26. Centris dentata, 



Male, Length 7i lines. — Black, the scape, clypeus, labrum 

 and mandibles yellow, at the base of the clypeus two abbreviated 

 black stripes ; the flagellum rufo-testaceous beneath ; the cheeks 

 densely clothed with pale pubescence, that on the vertex fulvous. 

 Thorax clothed with fulvous pubescence, palest on the raetatho- 

 rax ; the wings subhyaline, the tegulse pale testaceous ; the legs 

 rufo-testaceous, the posterior pair much darker than the others, 

 their femora incrassate, and armed in the middle beneath with a 

 short stout curved spine; the tibise and basal joint of the posterior 

 tarsi densely fringed with black pubescence. Abdomen, the base 

 and the apical segments clothed with fulvous pubescence. 



Hah. Brazil (Rio Tapajos). 



27. Centris sponsa. 



Female. Length 11 lines. — Black, the collar has a broad 

 band of short ochraceous velvety pubescence, which is continued 

 down the sides, not beneath ; the metathorax has a mixture of 

 ochreous pubescence ; the wings dark fuscous, opake, and having 

 a metallic-green iridescence ; legs black. Abdomen, the first 



