a Family of the Hymenoptera Heterogyna. 317 



behind the vertex towards the occiput, where it is very dark chestnut ; 

 face covered with decumbent down and in front of the anterior ocelli 

 slightly prominent, flattening as it descends between the base of the 

 antennae, (where there is a triangular smooth shining space,) which are 

 setaceous and inserted in a rather deep cavity, with their scape rather 

 less than one-fourth the length of the entire organ ; ocelli disposed in 

 a triangle, with a space of less than the diameter of one between the 

 anterior one and the posterior pair ; eyes very prominent ; mandibles 

 elongate, acuminate, slightly curved at the apex. 



Thorax gibbous in front and at the scutellum ; metathorax longer than in 

 the preceding species and less distinctly emarginated ; superior wings 

 subhyaline, clouded only within the marginal cell; the nervures dark 

 brown ; the cubital nervure very slightly undulated as far as the sepa- 

 ration of the two submarginal cells, and the recurrent nervure inserted 

 at fully one half of the length of the first of the latter and curving 

 slightly outwards; legs as in the preceding. 



Abdomen as in the preceding, the peduncle rather less transverse, and its 

 produced ventral portion rather boat-shaped, and the horizontal plate 

 of the male sexual organ constricted near the furcation of the spines, 

 which are divergent. 



In my own collection. 



This species is from the vicinity of the river Gambia ; it is very 

 like the preceding, and a superftcial examination might consider it 

 merely a smaller variety of that insect ; but a more careful inspection 

 discovers a number of particulars which establish its individuality — 

 which a comparison of the descriptions will show ; the strongest of 

 them are the different proportions of the cells of the wings and the 

 structure of the plate of the male organ. 



Sp. 4. Dor. glabratus, Shuck. Length 14| lines. 



Expansion 22k lines. 

 Rufo-brunneus, glaber, subrobustus, nervis alarum nigris, vertice valde 

 pro7ninente facie in medio sulcata, mandibulis altenuatis, labro tuberculit 

 binis obtusis instructis et pedunculo abdominis transverso-quadrato. 

 Rather robust, of a reddish fuscous-brown, glabrous with the exception of 

 some loose curling long hair upon the face, coxae, and extreme apex 

 of the abdomen. The head reddish chestnut, except behind the vertex, 

 where it is black and siiining. The face (which is covered with long 

 curling hair) and vertex very gibbous, and this gibbous portion viewed 

 laterally much larger than the eye; the face deeply longitudinally sul- 

 cated : ocelli placed in a triangle, the posterior pair upon the poste- 

 rior declivity of the head, and with rather more than the diameter of 

 one between the latter and the anterior one; eyes moderately large, 

 very prominent; antennae short, setaceous, the scape rather less than 

 one-third the length of the organ ; mandibles slightly curved, broad at 



