6 PROCEEDINGS OF THE NATIONAL MUSEUM, ym..6-i 



are very closely i-elated to those which have been assi2;ned to Psendo- 

 methoca, and have been so treated by Fox (1899) and by Bradley 

 (1916). Bradley (1916) reduced Nomiaephaf^us to snbgeneric rank, 

 making it a subgenus of Psevdo?n efhoca. I have been unable to find 

 characters of sufficient value for separating these two groups of 

 species even as subgenera and therefore unite them here under the 

 one genus Psendomethoca. In the sense used in this paper the species 

 of Pseudomethoca may be separated from all of the other North 

 American forms by the following characters: eyes round or slightly 

 oval, entire, not emarginate : pubescence of the body composed en- 

 tirely of simple hairs; first segment of the abdomen entirely sessile 

 with the second, the apex of the first segment being of the same size 

 as the base of the second ; a longitudinal carina always present on the 

 genae of the females. 



KEY TO THE SPECIES. 



FemaJes. 



1. Head spinose or dentate beneath 2 



Head not spinose or dentate beneath 7 



2. Head thickly clotlied with appressed, silvery pubescence S 



Head more or less bare, not thickly clothed with appressed, silvery 



pubescence 5 



3. Size large, 13 mm. ; ventral, postero-lateral angles of head sharply angulate, 



or dentate 12. cephalargia, new species. 



Size small, 3-5 mm. ; ventral, postero-lateral angles of head carinate, 

 but not sharply angulate, or dentate 4 



4. Carina of postero-lateral angles prominent, sharp, extending upon the 



vertex 6. toumeyi Fox. 



Carina of postero-lateral angles not prominent, not extending upon the 

 vertex 7. bequaerti, new species. 



5. Genae beneath bidentate 4. nephele Fox. 



Genae beneath unidentate 6 



6. Front produced at the base of the antennae into a thin, bidentate lamella 



2. dentifrontalis Bradley. 

 Front not so produced 1. canadensis Blake. 



7. (1) Greater part of abdomen ferruginous, or yellowish 8 



Abdomen black, except first and last segments 14. wickhami Cockerell. 



8. Dorsum of propodeum with a large, prominent, rugose tubercle at the apex 



medially 13. donae-anae Cockerell and Fox. 



Propodeum without any such tubercle 9 



9. Dorsum of body densely clothed with erect and semierect pubescence 10 



Dorsum of body thinly clothed with pubescence 13 



10. Head distinctly wider than the thorax; pubescence of dorsum of body 



fulvous 19. Jiarpalyce Fox. 



Width of head and thorax about equal 11 



11. Pubescence of dorsum of head, thorax, and abdomen concolorous 12 



Pubescence of head and thorax black, that of the second dorsal tergite 



golden 22, pigmentata, new species. 



