52 HYMENOPTERA. 



cell, the apical margins faintly clouded. Abdomen : the margins 

 of the segments constricted ; the basal segment with a fascia, 

 and the second, third, and fourth with an interrupted one a 

 little before their apical margins, the fascia widened at the lateral 

 margins of the segments ; the apical segment rugose, with elon- 

 gate punctures. 



Hob. Brazil (Santarem). 



178. THYNNUS PLAGIATUS. 



Male. Length 7-J- lines. Black: the clypeus, sides of the 

 face, a spot above each antenna, the mandibles, and head be- 

 hind the eyes, yellow. Thorax : the anterior and posterior 

 margins of the prothorax, a quadrate spot in the middle of the 

 mesothorax, the tegulae in front and a spot behind them, the 

 scutellum, post-scutellum, and metathorax, yellow ; the femora 

 yellow beneath ; the anterior tibiae and all the tarsi ferruginous ; 

 the wings hyaline, the nervures ferruginous ; a fuscous spot oc- 

 cupies the apex of the marginal cell and the third submarginal 

 cell. Abdomen : the first and four following segments with a 

 large ovate yellow spot on each side. 



Hab. South America. 



179. THYNNUS (AGRIOMYIA) GRATIOSUS. 



Male. Length 9 lines. Black : finely punctured on the head 

 and thorax ; the seven apical joints of the antennae arcuate ; the 

 inner orbits of the eyes, the lower portion of the outer orbits, a 

 narrow line on the posterior margin of the vertex, which unites 

 with the yellow line on the cheeks and is interrupted in the 

 middle above, a spot between the ocelli, another at the insertion 

 of each antenna, a spot on the clypeus, and the mandibles, yellow. 

 Thorax : the anterior and posterior margins of the prothorax, 

 three small oblong spots on the mesothorax, a line over the 

 tegulae, a spot on the scutellum and a smaller one at its basal 

 angles, the post-scutellum, and the sides of the metathorax, 

 yellow, the latter with a large irregularly-shaped black blotch ; 

 an irregular curved stripe beneath the wings, the femora beneath, 

 and the coxae spotted with yellow; the wings fulvo-hyaline. 

 Abdomen : the four basal segments yellow, with their basal and 

 apical margins ferruginous, and a number of small ferruginous 

 spots at the lateral margins ; an oblong black stain on the basal 

 segment, emitting a short fork on each side at its apex; the 

 sixth segment with an angular reddish-yellow spot on each side. 



Hab. South America. (Coll. W. W. Saunders, Esq.) 



