26° cw NATURAL HISTORY OF WASPS. 
social to the solitary group is very abrupt. And the 
two species which represent the solitary group seem 
forced into an unnatural position, when united with 
the typical genus Vespa of the social group, to the 
neglect of their more obvious relationships. But in 
the Exotic Fauna, where all the connecting links are 
supplied, this objection disappears. The Vespide 
shade into the Eumenide by as gradual steps as 
these do into the Fossores, clinging by their anatomy 
to the former, by their habits to the latter division. 
And, since some artificial distinction must"be adopted, 
perhaps that which the folding of the front wings 
supplies is as little arbitrary as any other. 
The EUMENIDA, or solitary group, are very widely 
distributed over the surface of the globe. Perhaps 
they are less variously represented in Great Britain 
than in most other places ; for we have only one very 
local species, Humenes coarctata, and twelve varieties 
of Odynerus, or of kindred species not readily dis- 
tinguishable from it. The natural histgry of the 
solitary wasps does not come within the proper scope 
of these remarks, so I will not enter upon it at 
length, but only give a short sketch, as far as they 
have come casually under my observation, of the 
appearance and habits of the Odyneri, which, to most 
of us, typify the British Eumenide. 
They are small, dark-looking wasps, having the 
abdomen banded with black and yellow in the 
strongest contrast, the black generally predominating. 
The abdomen is spindle-shaped, taperimg off at each 
end. The head is broad and flattened, the compound 
eyes large and projecting. The mandibles are long 
