38 HYMENOPTERA. 



with a smooth shining space at the base ; the rugose portion of 

 the segments covered with cinereous pubescence. 



Hab. Australia. 



99. Thynnus (Agriomyia) iridipennis. 



Male. Length 3i lines. — Black, shining, and punctured : the 

 anterior margin of the clypeus and of the face, and a spot at the 

 base of the mandibles, white ; a minute spot above each antenna 

 and a minute obscure one at the summit of the eyes yellow ; 

 the head with long thin cinereous pubescence. Thorax : an 

 obscure line on each side of the anterior margin of the prothorax, 

 the posterior margin, the tegulae, a spot on the scutellum, and 

 the post-scutellum, obscure yellow ; the calcaria and spines of 

 the tarsi white ; the wings hyaline and splendidly iridescent, the 

 nervures testaceous. Abdomen : the margins of the segments 

 constricted ; beneath, the apical segment truncate, the angles of 

 the truncation with minute teeth, and with a longer acute one in 

 the middle. 



Female. Length If line. — Obscure rufo-testaceous : head 

 smooth and shining ; thorax sparingly punctured ; the legs, basal 

 and apical segments of the abdomen pale rufo-testaceous ; the 

 second segment with two transverse carina;. 



Hab. Australia (Lower Plenty). (Coll. R. Bakewell, Esq.) 



100. Thynnus (Agriomyia) truncatus. 



Male. Length 4-4^ lines. — Black, slightly shining, and thinly 

 clothed with cinereous pubescence : the clypeus truncate ante- 

 riorly, the margin on each side of the truncation, a spot at the 

 base of the mandibles, a narrow line on each side of the anterior 

 margin of the prothorax, and the post-scutellum, or a line upon 

 it, yellowish-white ; the wings hyaline, the nervures black. The 

 margins of the segments of the abdomen deeply constricted ; 

 beneath, the apical margins narrowly testaceous, the terminal 

 segment truncate, or slightly emarginate its entire width at its 

 apical margin ; in the middle of the einargination an acute spine. 



Hab. Australia (Lower Plenty, Victoria). (Coll. R. Bakewell, Esq.) 



101. Thynnus (Agriomyia) trivialis. 



Male. Length 4 lines. — Black : head and thorax closely 

 punctured and opake, the metathorax and abdomen smooth and 

 shining, the former very delicately reticulated. The anterior 

 margin of the clypeus and of the face, as well as the mandibles, 

 yellow; the legs ferruginous, the coxae and trochanters black, 

 the claw-joint of the tarsi fuscous; the anterior and posterior 



