a Family of the Hymenoptera Heterogyna. 191 



tained except by St. Fargeau*, although he says apparent analogy 

 induces him to leave them together. To me however it is evident 

 that, with the exception of the small difference in the neuration of 

 the wings, the genera are very much alike, and this affinity is still 

 further proved by means of the new genus I describe below by the 

 name of Mnictus ambiguus, which deprived of its wings might 

 easily pass for a Labidus, it having the same kind of canaliculated 

 peduncle to the abdomen, and legs like the latter, for neither femora 

 nor tibiae are compressed as in the typical Doryli. 



In reviewing the arguments urged by St. Fargeau for placing these 

 genera with the Social Ants in opposition to the views of Latreille, I 

 cannot think that founded upon the structure and relative propor- 

 tions of the antennae of any value at all, as in the several species of 

 each of these genera the structure and proportions of these organs 

 differ considerably; and besides this, in very many of the males of 

 the Social Ants, indeed, I may say in the majority of them, the 

 scape or first joint of the antenna is not one-third of the length of 

 the entire organ. In the structure of the mandibles, which he also 

 cites in support of his opinion, there are, especially in the genus Z)o- 

 rylus, considerable differences in the species, and nothing can be 

 more fallacious than to suppose that the structure of these organs in 

 the genus Dorylus can possibly indicate sedificatorial habits ; for they are 

 edentate, forcipate, and considerably slighter in proportion than the 

 male mandibles in the great majority of the genera of the well-known 

 solitary Heterogyna : and his argument from the structure of the 

 wing is not so strong as he might have made it if he had adduced 

 the single recurrent nervure, which is a structure never found in the 

 normal solitary Heterogyna, for they have invariably two recurrent 

 nervuresf. I admit that the mere absence of the females proves 

 nothing as to the solitary habits of these genera, although I think 

 with Latreille as above cited, that the presumption is in favour of 

 their being so. 



In confirmation of St. Fargeau' s views, Mr. Haliday, as I observed 

 above, has formed these two genera into a family, and has placed 

 them in the same tribe with the Social Heterogyna, making them 

 equivalent to the whole of this tribe ; and in corroboration of St. Far- 

 geau, he says, " Dorylidas societate victuros more Formicarum con- 

 tendit Peletierus argumentis equidem gravissimis, quibus adjicienda 



* Hist, des Hymenopt. vol. i. p. 227. 



t Certainly with the exception of the genus Jpterogijna, which is another 

 anomalous form, and which seems to be also another connecting link at a 

 different point with the Social Heterogyna. 



