HYMENOPTERA. 419 



golden ])ubescence ; the tnidclle of the mandihles and the scape 

 yellow. Thorax : a spot on each side of the collar, the tubercles, 

 and a spot in the middle of the post-scutellum, j'ellow; the 

 mesothorax longitudinally roughened ; the scutellum shining 

 and with longitudinal punctures ; the metathorax with a deep 

 central longitudinal channel, which is transversely striated ; the 

 base of the metathorax coarsely obliouely striated, posteriorly 

 transversely so ; the wings slightly coloin-ed, the nervures nifo- 

 testaceous; the tibice and tarsi yellow; the claw -joint fuscous, 

 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 pinched at the sides and 

 covered with yellow pubescence; beneath, immaculate. 



The male closel3' resembles the female, but has a silver}- pu- 

 bescence on the cl}']3eus, and the spots on the collar and post- 

 scutellum obliterated; the fasciae on the abdomen reduced to 

 oblong lateral spots; the tibiae 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. 6-maculatus?). 



Hob. Pennsylvania ; Hudson's Bay. 



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

 garded as the American representative of it : the yellow markings 

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

 as in C. vagus, and are apparently 12-joiuted, as in that sjjecies. 



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 metathorax with a sub- 

 defined half- circular sj)ace at its base, which is coarsely striated 

 obliquely ; posteriorly 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 snbdentatc ; the knees, tibiae 

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

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



