HYMENOPTERA. 419 



golden pubescence ; the middle of the mandibles and the scape 

 yellow. Thorax : a s]iot on each side of the collar, the tubercles, 

 and a s])ot in the middle of the post-scutelhim, yellow ; the 

 mesothorax louiiitudinally roughened ; the scutellum shining 

 and with longitudinal punctures ; the mctathorax with a deep 

 central longitudinal channel, which is transversely striated ; the 

 base of the mctathorax coarsely obliquely striated, posteriorly 

 transversely so ; the wings slightly coloured, the nervures nifo- 

 testaccous; the tibia? and tarsi yellow; the claw -joint fnscous, 

 as well as the second, third and fourth joints of the posterior 

 pair. Abdomen smooth and shining, the second, third and fourth 

 segments with a yellow fascia on their basal margins, the first 

 three interrupted ; the apical segment ])inclied at the sides and 

 covered with yellow pubescence ; beneath, immaculate. 



The male closely resembles the female, but has a silvery pu- 

 bescence on the clypeus, and the spots on the collar and post- 

 scutellum obliterated ; the fascia; on the abdomen reduced to 

 oblong lateral spots; the tibia? have a black stain beneath. 



Hab. Hudson's Bay. (Coll. G. Barnston, Esq.) 



135. Crabro trifasciatus. B.M . 



Crabro trifasciatus, Say, Narr. Exped. St. Peter^s River, Append, 

 p. 74. 4 (var. G-maculatus?J. 



Hab. Pennsylvania; Hudson's Bay. 



This species scarcely differs from C. vagus, and may be re- 

 garded as the American representative of it : the yellow markings 

 are much paler ; the antennae of the male are of the same form 

 as in C. vagus, and are apparently 12-jointed, as in that species, 



136. Crabro frigidus. B.M. 



Female. Length 5| lines. — Black : the head finely punctured, 

 the cheeks sparingly so, smooth and shining; the ocelli in a 

 curve on the vertex ; the scape and mandibles yellow, the base 

 and apex of the latter black. Thorax : the mesothorax longitu- 

 dinallv striated ; the scutellum shining, punctured at the base, 

 and longitudinally striated beyond ; the mctathorax with a sub- 

 defined half- circular space at its base, Avhich is coarsely striated 

 obliquely ; ])osteriorly it is very coarsely and deeply rugulose ; a 

 spot on each side of the collar and the tubercles yellow, the an- 

 terior lateral angles of the collar subdentate ; the knees, tibiae 

 and tarsi yellow, the apical joints of the latter fuscous, the ex- 

 treme apex of the tibia; with a ferruginous stain; the wings 



