JAMES A. G. REHX 239 



Mestobregma impexum>^ new species (Plate XXVI, figs. 9 and 10; plate 

 13 and 14.) 



1910. Mestobregma rubripenne Rehn and Hebard (not of Bruner, 1905), 

 Proc. Acad. Nat. Sci., Phila., 1909, p. 442. [Cima and Bird Spring Moun- 

 tains, California.] 



The present species can be separated from the component 

 races of Mestobregnia plattei (see plate XXVI, figs. 11 and 12; 

 plate XXVIII, figs. 11 and 12) by its more robust form, more cir- 

 cular basal eye outline, the much less angulate fastigio-facial 

 angle when seen in profile, and by the sharp and decided constric- 

 tion of the frontal costa briefly dorsad of the antennal bases. 

 From M. terricolor, here described, the present species differs in 

 the more inflated genae, the less decided fastigio-facial angle 

 when seen in profile, in the frontal costa constriction, in the 

 more distinct mesozonal section of the pronotal median carina, 

 in the shorter lateral lobes of the pronotum, the shorter and more 

 robust form and more contrasted coloration. 



Type.— d'; Milford, Beaver County, Utah. Elevation, 4900 

 to 5000 feet. September 5, 1909. (Rehn and Hebard.) [Heli- 

 ard Collection, Type no. 494.] 



Description of Type. — Size medium: form slender, subcompressed : pronotum 

 rugose on dorsal surface. 



Head moderately inflated, the genae moderately bullate and with the 

 width across same slightly more than greatest width across eyes : occiput and 

 vertex, when seen from side, distinctly arcuate, ventro-cephalad markedly 

 and sinuately arcuate declivent to the rounded and weakly indicated fastigio- 

 facial angle, which is situated between the antennal bases; face subvertical: 

 fastigium with length and breadth subequal, very shallowly excavate; lateral 

 carinae of fastigium low but clearly marked, subparallel caudad, converging 

 cephalad to about one-half their median separation, the cephalic margin of 

 the fastigium indicated by a more weakly defined, narrowly V-shaped (;arina, 

 the apex directed caudad: frontal costa appreciably V-foveolatc dorsad at its 

 junction with the fastigium, the foveolation in contact with the V-shaped 

 carina of the fastigium, immediately ventrad of this the costa is first strongly, 

 although regularly, constricted, then arcuately expanded between the anten- 

 nae, at the constriction and dorsad to the foveolation with an appreciable 

 median carina, ventrad of inter-antennal region very faintly constricted, then 

 with margins weakly diverging and becoming obsolete before reaching the 

 clypeal suture; marginal carinae of frontal costa distinct but low, surface of 

 costa ventrad of foveolation very weakly excavate: lateral facial carinae 

 strongly arcuate divergent. Eyes moderately prominent, not elevated dorsad 

 of vertex when seen in ce])halic aspect ; basal outline very broad ovate, in dejith 

 subequal to the infra-ocular sulcus. Antennae slender, nearly twice the 



'^ Rude, uncouth — from the rough appearance of the pronotal disk. 



TRANS. .\M. ENT. SOC, XLV. 



