British Hiimenoptera. 187 



Prosopis, Fah. 



Fab., Syst. Piez., p. 293. For figures of generic 

 characters see F. Smith, Cat. Brit. Hym., '2nd eel., 

 pi. vi., and for figures of 7th and 8th ventral segments 

 of all the species see this vol., antea, pi. vi. 



Tongue short, obtuse, somewhat bifid. Maxillary palpi 

 6-jointed ; labial palpi 4-jointed ; anterior wings with 

 two submarginal cells. 



A genus of small coal-black bees, with scarcely any 

 pubescence, and with the abdomen generally shining and 

 polished, the tibiae generally more or less variegated with 

 yellow ; the face in the ^ white, except in one species 

 (cornuta), in the 2 generally with two yellow spots. 



(2) 1. (J ; face black, excavated and shining above the 



insertion of the antennae. J ; face with two 



short spines . . . . . . . . . . . . cornuta. 



(1) 2. ^ ; face white. $ ; face simple. 



(6) 3. 1st segment of abdomen with no lateral white pube- 



scence at the apex. 

 (5) 4. Scape of antennsB in ^ flattened, dilated, and white 



anteriorly. J ; spots of face nearly round, 



situated in the middle just below the antenna . . dilatata. 

 (4) 5. Scape of antennae in ^ not flattened and dilated. 



5 ; spots of the face moi-e or less lateral. . . . coinmiinis. 



(3) 6. 1st segment of abdomen at the apex with a narrow 



line of silvery pubescence at each side. 

 (10) 7. Larger species. ^ with the extreme base only of 

 the 1st joint of the hind tarsi pale ; J with the 

 1st segment of the abdomen largely and some- 

 what closely punctured. 



(9) 8. Face longer in both sexes. (J with the white colour 

 extending high above the insertion of the antenna 

 at the sides ; mandibles with a white line. J with 

 two long narrow spots along the margins of the 

 eyes, extending from above the antenna almost 

 to the base of the mandibles . . . . puiictulatissiina. 



(8) 9. Face shorter in both sexes. $ with the white 

 colour not extending above the insertion of the 

 antenna ; mandibles black. J with a white spot 

 on the margin of the eyes, sometimes wanting . . signuta. 



(7) 10. Smaller species. ^ with the whole, or nearly the 



whole of the basal joints of the posterior and 

 intermediate tarsi yellow. 5 with the 1st segment 

 of the body very finely or irregularly punctured. 

 (16) 11. Scape of the antenna in the ^ more or less swollen ; 

 spots of the face in the J subtriangular or linear, 

 lateral, and parallel in direction to the inner mar- 

 gins of the eyes. 



