a Family of the Hymenoptera Heterogyna. 259 



Thorax subfuscous, very gibbous both in front and at the scutellum, the 

 latter longitudinally sulcated in the centre; superior wings with their 

 nervures pale testaceous ; marginal cell regularly lanceolate, consider- 

 ably larger than either of the two first submarginals, and rounded within 

 the first submarginal, which is rather smaller than the second, from 

 which it is separated by an inwardly curved transverso-cubital nervure ; 

 the recurrent nervure inserted at less than one half the length of the se- 

 cond submarginal cell, and beyond which, and as far as the second trans- 

 verso-cubital, the cubital nervure is considerably thickened : legs short 

 and slender. 



Abdomen shining, the base of all the segments constricted, the peduncle 

 as wide as the following segment, transverse quadrate, the posterior 

 angles truncated, plane above with a transverse convex ridge at its 

 apex, and its ventral portion viewed laterally produced in the middle 

 into an acute tubercle. The terminal segment vertically much com- 

 pressed at its extreme apex, where it has a deep fissure, and the 

 sexual organ protruding in the form of a deeply emarginate plate, ter- 

 minating on each side in a compressed acuminated spine. 



In the collection of the Rev. F. W. Hope. 



This species, which was also captured by Mr. Swainson in the 

 Brazils, is distinguished from all the rest I know by its longitudi- 

 nally sulcated scutellum : other prominent differences are supplied by 

 the relative proportions and form of the marginal and cubital cells 

 and the insertion of the recurrent nervure. 



Sp. 7- Lab. D'Orbignii, Shuck. Length 6§ lines. 



Expansion of the wings 12 lines. 

 Niger, brunneo-holosericeus, pedunculo abdominis semicirculato supra sub- 

 con ve.ro, nervis alarum brunneo-testaceis. 



Black, covered with a close brownish silky down. Head having the ocelli 

 small and placed in a very open curve at the vertex, and with an ele- 

 vated carina connecting the posterior pair, the carinae of the face 

 curving off and terminating in front of the anterior one ; antennae 

 fulvous beneath, moderately long, and thickest at the base, the scape 

 rather less than one-fifth the length of the organ : mandibles moderate, 

 very slender, and leaving a nearly semicircular space between them and 

 the clypeus. 



Thorax very gibbous in front and at the scutellum : superior wings with 

 the nervures brownish testaceous; the marginal cell short and broad, 

 extending but a little way beyond the apex of the second submarginal 

 cell, where it is angulated; the first submarginal larger than the second, 

 from which it is separated by a slightly inwardly curved nervure; the 

 second submarginal rather narrow, and having the recurrent nervure 

 inserted at about half its length, where immediately at the junction the 

 cubital nervure is slightly thickened : legs short and slender, loosely 

 covered with long hair. 



T 2 



