348 PROCEEDINGS OF THE NATIONAL MUSEUM vol.93 



Fore tibia (pi. 29, fig. 4) of the usual Hylocums structure, 

 widened distally, both sides sinuate, terminal mucro strong, its end 

 recurved; distal end oblique, with five submarginal teeth. 



The male is unknown. 



Type locality. — Orange County, Calif. 



Hosts. — Rhus laurina Nuttall and R. integrifolia (Nuttall) B. 

 and H. 



Type material. — Holotype and five paratypes, U. S. N. M. No. 

 56401. The type series was collected October 24, 1934, by W. Ebeling, 

 from the two species of Rhus cited above. 



Genus MICRACIS LeConte 



Micracis LeConte, Trans. Amer. Ent. Soc, vol. 2, pp. 164-165, 1868; Proc. Anier. 

 Phil. Soc, vol. 15, pp. 367-368, 1876. — Eichhoff, Ratio Tonrinicorum, Mem, 

 Soc. Roy. Sci. Liege, ser. 2, vol. 8, pp. 302-304, 1878.— Swaine, Canada 

 Dept. Agr., Ent. Branch, Bull. 14, pt. 2, p. 83, 1918. — Blackman, Mississippi 

 Agr. Exp. Stat. Techn. Bull. 9, pp. 8-35, 1920 ; New York State Coll. Fores- 

 try Techn. Publ. 25, pp. 192-197, 1928. 



Genotype. — Micracis suturalis LeConte. 



The genus Micracis in the restricted sense used in this paper con- 

 tains 10 valid species as follows: suturalis LeConte (synonym 

 aculeatus LeConte), hirtellus LeConte, acutipennis Eichhoff, meri- 

 dianus Blackman, populi Swaine, swainei Blackman, cubensis 

 Blackman, lignator Blackman, dimorphus Schedl, and knulli, new 

 species, described below. Of these acutipennis and dinwrphus occur 

 in Brazil and cubensis is from Cuba, while the other seven species 

 occur in continental United States. 



MICRACIS KNULLI, new species 



Plate 29, Figures 5, 6 



Female. — Dark reddish brown; 2.59 mm. long, 3.19 times as long 

 as wide; allied to lignator Blackman but much smaller. 



Frons convex above, with surface hidden by numerous moderately 

 long, stout, spatulate bristles, sordid yellow in color and directed 

 dorsad; lower frons somewhat flattened between eyes, the middle 

 third bare, subopaque, distinctly reticulate, without punctures, lateral 

 third densely covered by yellow hairs, finer and longer than those 

 above. Eye long oval, moderately separated beneath, moderately 

 coarsely granulate, with inner margin slightly sinuate. Antenna 

 (pi. 29, fig. 5) testaceous, scape flattened, moderately strongly dilated 

 distally, and ornamented by long, fine hairs; club flattened, with 

 narrowly arcuate sutures, about 1.64 times as long as wide. 



Pronotum 1.16 times as long as wide, slightly widest near middle, 

 posterior outline feebly arcuate, posterior angles rounded; sides nearly 



