84 HYMENOPTERA. 



nearly triangular, produced in the form of a beak, having a 

 convex space at the base, from which an elevated carina passes 

 forwards to the apex ; the carina broadest at its base, in which 

 is a deep fossulet. Thorax globose, the superior wings having 

 one marginal and three submarginal cells, the second being in 

 the form of an oblong square placed a little obliquely and re- 

 ceiving the first recurrent nervure near or at its apex ; the second 

 submarginal cell also receives near its apex the second recurrent 

 nervure. Abdomen ovate, the fifth segment having a central 

 rima in the female. 



1. MEGALOPTA BITUBERCULATA. 



Male. Length 4 lines. Head, the vertex black, the face 

 below the insertion of the antennae rufo-testaceous and covered 

 with pale fulvous pubescence, the mandibles rufo-testaceous, their 

 apex ferruginous ; antennae fulvous, slightly fuscous above. 

 Thorax testaceo-ferruginous, having two longitudinal pale indi- 

 stinct stripes on the disk ; the scutellum on each side raised into 

 a somewhat conical tubercle ; beneath the post-scutellum the 

 base of the metathorax has a space enclosed by an arched carina; 

 beneath covered with pale pubescence ; wings hyaline, nervures 

 ferruginous ; legs pale testaceous. Abdomen ferrugineo-testa- 

 ceous, smooth and shining, the margins of the segments paler ; 

 at the base and towards the apex is a little pale fulvous pubes- 

 cence. 

 Hab. Brazil. (Coll. F. Smith.) 



2. MEGALOPTA IDALIA, n. s. B.M, 

 Halictus amcenus, Spin. Mem. Accad. Torino, xiii. ? 



Female. Length 5-6 lines. Head and disk of the thorax 

 brassy-green ; antenna?, margin of the clypeus, labrum and man- 

 dibles ferruginous, the latter black at their tips, the clypeus 

 roughly, but the head otherwise finely and closely punctured. 

 Thorax very finely punctured ; the metallic portion of the disk 

 extends to the post-scutellum, beyond which the thorax is ferru- 

 ginous, the sides beneath the wings being suffused with metallic 

 green ; the tegulae and legs testaceo -ferruginous, the neuration 

 of the wings of the same colour ; wings hyaline. Abdomen tes- 

 taceo-ferruginous, having a scattered fulvous pubescence, and 

 being of a paler colour beneath. 



Male. This sex corresponds in every particular of colour and 

 sculpture, the apical joints of the antennae being fuscous above, 

 the extreme apex ferruginous, the basal joint being pale testa- 

 ceous beneath. 

 Hab. Brazil ; banks of the Amazon and Para. 



