280 HYMENOPTERA. 



bears longish, rather dense, hair. Abdomen closely punctured, pilose; petiole depressed 

 in the centre at the base ; two stout, slightly converging, keels run from the base to 

 near the middle; genital organs projecting, fuscous. Legs stout; the femora and hind 

 tibiae thickened ; the coxae and tarsi of a lighter tint than the femora and tibiae. 



Obs. It is possible that what I have called " flavo-rufo " may be a pure yellow (which 

 is nearly the colour of the line on the pronotum), the reddish tint being discoloration, 

 perhaps caused by cyanide of potassium. 



3. Exochus tricarinatus. 



Exochus tricarinatus, Cresson, Trans. Am. Ent. Soc. 1868, p. 38 (<?); Proc. Acad. Phil. 1873, 

 p. 392 \ 



Hab. Mexico, Hacienda del Potrero, near Cordova * (Sumichrast). 



4. Exochus pulchripes. 



Exochus pulchripes, Cresson, Trans. Am. Ent. Soc. 1868, p. 38( C J) 1 ; Proc. Acad. Phil. 1873, 

 p. 393 2 . 

 Eab. Mexico, Hacienda del Potrero, near Cordova \ Orizaba 2 (Sumichrast). 



5. Exochus melanocephalus. 



Eufo-testaceus, capite abdominisque apice nigris ; facie oreque rufis ; alis hyalinis, nervis nigris. <3 . 

 Long. 6 millim. 



Hab. Mexico, Northern Sonora (Morrison). 



Antennae moderately stout ; blackish, testaceous at the basal fourth ; basal joint of 

 the scape cylindrical, stout, scarcely one half longer than thick; first joint of the 

 flagellum nearly double the length of the fourth. Face finely punctured; vertex 

 shining ; a sharp keel runs down from the ocelli to the antennae, the space on each 

 side . of it being slightly excavated. Thorax shining ; metanotum slightly aciculate ; 

 two keels run down its sides ; beyond what is enclosed by these two keels there are no 

 areee. Abdomen shining, impunctate, thickened towards the apex ; the ventral surface 

 pallid testaceous. Legs (especially the femora) stout, pallid testaceous at the base; 

 the tarsi paler in tint than the tibiae, their apices fuscous. Areolet angled on the lower 

 side where the recurrent nervure is received beyond the middle. 



B. Areolet present. 



6. Exochus caeruleiventris. 



Exochus cceruliventris, Cresson, Trans. Am. Ent. Soc. 1868, p. 38 ( <S ) L ; Proc. Acad. Phil. 1873, 

 p. 392 2 . 

 Hab. Mexico, Hacienda del Potrero, near Cordova 1 , Orizaba 2 (Sumichrast). 



