NORTH AMERICAN HYMENOPTERA. 167 



those on the latter segment sometimes reduced to dots, yellowish white ; ])ale hair 

 on vertex and cheeks rather prominent ; silvery pubescence in usual situations ; 

 wings subhyaline, but little darker apically, uervures and stigma dark testaceous. 

 Length 7.5-8 mm. 



% . — More coarsely sculptured than in 9 > head striated in front, above and on 

 cheeks rather coarsely and closely punctured ; flagellum broadest basally, the 

 first joint with a bunch of white hairs beneath ; anterior margin of clypeus with 

 a prominent quadrate production medially ; cheeks strongly depressed below ; 

 prouotum with a small tooth laterally ; dorsulum closely but less coareely punc- 

 tured than occiput ; mesopleurge with the epimerum above striated similarly to 

 its episternum: middle segment with sides more coarsely striated, the posterior 

 face more rugose, the lateral ridges longer, reaching the upper surface, first joint 

 of medial tarsi scarcely one-third longer than the length of the remaining joints 

 united ; tibial shield somewhat longer than broad, the lower margin almost 

 straight, not sinuate or emarginate, posteriorly the shield rounded, in color brown- 

 ish in greater part, otherwise greenish, narrowly streaked with yellow, yellow 

 also at extreme base ; mai-ked very much as in the 9 1 except as follows : no yel- 

 low on scutellum, and tubercles, fore femora almost entirely, middle femora with 

 a stripe anteriorly and posteriorly, a line on hind tibiae, anteriorly and posteriorly 

 and a small spot on each side of ventral abdominal segment 2, yellowish. Length 

 8 mm. 



Colorado. The small size, sculpture of 9 > shape of tibial shield 

 of S , and shape of fore margin of clypeus are the chief points of 

 difference in this species. 



43. Crabro medium n. sp. 



'Jj . — Head coarsely and closely punctured, distinctly striated anteriorly ; space 

 between hind ocelli rather distinctly less than that between them and the nearest 

 eye-margin; flagellum not much broadened, widest medially, first joint without 

 bunch of hairs beneath ; cheeks coarsely striated, slightly depressed, not keeled 

 beneath ; pronotum strongly ridged anteriorly, particularly toward the sides, the 

 lateral tooth strong and sharp ; dorsulum and scutellum coarsely and closely 

 punctured ; epimerum mesopleuralis sparsely punctured, separated from the 

 mesosternum by a strong furrow, episterual suture strongly foveolate ; middle 

 segment very coarsely rugose, the ridges on upper surface forming foveas, on pos- 

 terior face transverse, and not so strong; lateral ridges exceedingly sti'ong, the 

 sides with irregular striations ; first joint of medial tarsi somewhat less than one- 

 third longer than the remaining joints united ; form femffra at base extended 

 into an acuminate production, which is nearly as long as that part of the femora 

 before its junction with the trochanter ; tibial shield rather small, obtuse apically, 

 outer margin being sinuated or once emarginate, in color the lower portion is deep 

 black, on remainder yellowish streaked with blackish. Black, including scape 

 posteriorly, and thorax entirely ; spot on mandibles medially, scape anteriorly, 

 greater part of fore femora, tips of medial pair and a spot before their apices, 

 tibise except a dark spot within and on fore pair without, first joint of tarsi, 

 sinuated spots on first abdominal segment, large spots on second, slender spots on 

 segments 3-6, all of which are separated medially, and usually though not always, 

 a lateral spot on ventrals 2 and 3, yellow ; clypeus either black or more or less 

 yellow ; pubescence on mesosternum rather long ; wings subfuscous, uervures 

 dark, the stigma paler, testaceous. Length 7-8.5 mm. 



TRANS. AM. ENT. SOC. XXII. JUNE, 1895. 



