DIPLOPTKRYGA MASARTD^. 123 



DIPLOPTERYGA. 



This series consists of the true wasps, and is characterized chiefly 

 by the wings being folded longitudinally in repose (more or less in- 

 distinctly so in the Masarid^e), in which respect it differs from all the 

 other series, except in the Chalcid genus Leucospis. The prothorax 

 is prolonged backwards to the base of the wings, the eyes are reni- 

 form and the legs are not formed for burrowing in the ground, being 

 free from spines and bristles. The solitary species consist of two 

 sexes, % and 9 , and somewhat resemble the Fossores in their habits, 

 constructing their nests in sandy banks, in crevices of stone-walls, in 

 holes bored by other insects in wood, etc., using their powerful man- 

 dibles in excavating ; some genera, e. g. Eumenes, construct mud- 

 nests, in the open air, on stems of weeds, or under leaves, or loose 

 bark of trees. On the other hand the social species consist of three 

 sexes, h , 9 and $ , and are natural paper makers, constructing 

 their nests on trees, or in corners of building, or under the roofs of 

 outbuildings, although some species, e. g. Vespa vulgaris and ger- 

 manica, commonly known as " yellow-jackets," build their nests un- 

 derground, as most country boys know by painful experience. A 

 very interesting article on the habits of these insects, by the late B. 

 D. Walsh, will be found in the first volume of the " American En- 

 tomologist," pp. 138-143. 



The series is divisible into three families, in the following manner : 



Table of Families. 



Antennae clavate or knobbed at tip, the joints of the elub generally soldered 

 together; scutellum large, narrowed and rounded posteriorly, super- 

 posed upon the postscutellum ; anterior wings indistinctly folded in re- 

 pose ; solitary, sexes % 9 MASARID^. 



Antennae filiform or subfiliform ; scutellum transverse, truncate posteriorly, not 

 superposed upon the postscutellum; anterior wings distinctly folded in 

 repose. 

 Intermediate tibiae with one spur at apex ; tarsal claws unidentate ; solitary, 



sexes % 9 EUMENID^. 



Intermediate tibia; with two spurs at apex ; tarsal claws simple : social, sexes 

 -^ 9 $< VESPID^. 



Family MASARIDiE. 



Thifi small, but beautiful family is at once recognized bv the clavate 

 or knobbed antennte, long in the males of Mmaris, and short in the 

 females and in both sexes of Evparagia ; the single species of the 



