84 HYMENOPTERA. 



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

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

 forwards to the a])ex ; the carina broadest at its base, in which 

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

 one marginal aiul three submarginal cells, the second being in 

 the form of an oblong square ])la('ed 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 j)ubescence, the mandibles rufo-testaceous, their 

 apex ferruginous ; antenna; fulvous, slightly fuscous above. 

 Thorax testaceo-ferruginous, having two longitudinal pale indi- 

 stinct strijies 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. Brazd. (Coll. F. Smith.) 



2. Megalopta Idalia, n. s. B.M. 

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



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

 brassy-green ; antennae, 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 ])aler colour beneath. 



Male. — This sex conesponds 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. 



