30 PROCEEDINGS OF THE NATIONAL MUSEUM vol.74 



Olypeus rather strongly convex, with a distinct reflexed margin ; mesoscutum 

 immaculate or with a single median spot; head in female unicolorous, in 

 male black and yellow, pale orbits interrupted at top of eye ; male antenna 

 with a pale annulus 7 



5. Thorax not at all red rufigaster, new species. 



Thorax partly or entirely red 6 



6. Pronotum and mesoscutum black and white confederata, new species. 



Pronotum and mesoscutum largely red alabama, new species. 



7. Thorax in female red, in male red and yellow; a small species. 



acadia, new species. 

 Thorax in female black, in male black and yellow ; a large species. 



introita (Cresson). 



DIAPETIMORPHA ORBA (Say) (new combination) 



Fig. 6f 



Cryptus orbus Say, Boston Journ. Nat. Hist., vol. 1, 1835, p. 231 (LeCk»nte 



ed., vol. 2, p. 688). T^/pe.— Lost; neotype in U.S.N.M. 

 Hemiteles orbus (Say) Walsh, Can. Ent., vol. 2, 1869, p. 9. — Cbesson, Synop. 



Hym. No. Amer., 1887, p. 199. 

 Mesostenus diliffens Cbesson, Can. Ent., vol. 10, 1878, p. 207, female. Type. — 



No. 1175, Acad. Nat. Sci. Phila. 

 Lymeon annuUcomis Ashmead, Ins. Life, vol. 7, 1894, p. 243, female. Type. — 



Cat. No. 1462, U.S.N.M. 

 Crypturopsis annulicornis (Ashnread) Cushman, Proc. U. S. Nat. Mus., vol. 55, 



1919, p. 521. (Possibly synonymous with diligens.) 

 Crypturopsis orbus (Say) Cushman and Gahan, Proc. Ent. Soc. Wash., vol. 



23, 1921, p. 162. 



Has very much the appearance of a species of Crypturo'psis but 

 with areolet distinctly pentagonal. 



Discussion based on neotype of orbus., type and homotype (Vier- 

 eck) of diligens., type of annulicornis., and 13 other females and 6 

 other males, all except the type of diligens in the United States 

 National Museum. 



Fetnal-e. — Length, 5-9 mm. 



Head very finely (coriaceous, temples and cheeks subpolished, frons 

 and vertex medially rugulose; face sparsely punctate and somewhat 

 rugulose just below antennae, with a shallow impression on each side 

 of middle just above clypeus. Temples very narrow and nearly flat ; 

 cheeks swollen; occipital carina slightly sinuate below; clypeus 

 strongly convex with a distinct reflexed margin; malar space two- 

 thirds basal width of mandible ; upper tooth of mandible larger and 

 longer than lower ; flagellum slender, neither thickened nor flattened 

 below toward apex, joint 1 about six times as long as thick, 2 and 3 

 somewhat shorter and subequal, 4 a little more than half as long as 

 3, others successively shorter. Thorax shining; pronotal impression 

 striate; mesoscutum opaque coriaceous, middle of disk irregularly 

 longitudinally striate, prescutum sparsely punctate, notauli foveo- 

 late ; scutellum polished, not margined ; mesopleurum partly and all 



