a Family of the Hymenoptera Heterogyna. 199 



far as the apex of the abdomen : the basal joint of the posterior tarsi 

 very robust. 

 Abdomen opake, curved downwards, the segments not constricted : the 

 peduncle subtrigonal, narrower than the following, rounded at the base, 

 concave and shining above, the posterior angles produced, and the ven- 

 tral portion smooth and not produced; the terminal segment vertically 

 but not acutely compressed at its extreme apex, where it is deeply 

 emarginate. 



In my own cabinet. 



This species is from Demerara I believe. The difference of size 

 prevents my considering it the type, which is the next ; this, although 

 not a conclusive point in the majority of insects, I think may by 

 analogy be considered so here, for in the genus Dorylus, in which I 

 have had the opportunity of examining many individuals of several 

 species, there is none or but a very immaterial difference in their 

 size. In the present genus I have seen but single specimens of any 

 species. To judge from the description, the distribution of colour, 

 and the structure, are apparently the same, excepting that in the 

 next the neuration of the wings is brown, whereas in this they are 

 of the same colour as the body. 



Sp. 3. Lab. Latreillii, J urine. Length 8 lines. 



Rufo-testaceus, pubescens : capite {mandibulis, antennisque except is) nigri- 

 cante ; pedunculo abdominis subtrigono, supra in medio piano, ad later a 

 elevato ; nervis alarum brunneis. 



Jurine, Nouv. Method. Hymenop., p. 282. 



Latreille, Genera Crustac. et Insect, iv. 123. 



Nouv. Diet, d'flist. Nat., 2 e ed. torn. xvii. 141. 



" Body reddish, pubescent. Head blackish, excepting the antennae and 

 mandibles, which are of the same colour as the body. Ocelli are placed 

 in a triangle on the vertex : the superior wings are of a bright fulvous 

 tint, and the nervures brown ; their marginal cell is oval and elongate ; 

 the first submarginal is nearly square, the second is smaller and receives 

 the recurrent nervure : the tibiae increase in thickness to their extre- 

 mity, and the calcar at their apex is broad at the base, as is also the 

 basal joint of the tarsi. 



" The abdomen is elongate and curved at its apex ; the peduncle has the 

 form of a saddle, the sides being raised/' 



This insect Latreille says is from Cayenne. I have not seen the 

 species, consequently his description given in the second edition of 

 the ' Nouveau Dictionnaire d' Hist. Nat.' is here repeated. It is 

 very probable that he received it from M. Jurine, who dedicated 

 the species to him. Others have frequently been mistaken for it, 

 but I think its size and other peculiarities sufficiently distinguish it 



