12 HYMENOPTERA OF AMERICA. [PART I. 



feet insects sustain themselves by Backing vegetation. The Ody- 

 nerime establish their nests in holes in walls, in the hollow interior 

 of the stems of certain plants, or in habitations which they con- 

 struct in the open air, of clay or of some vegetable and gummy 

 substances. The eggs deposited in these nests are abundantly 

 provided with larvae or insects stupefied and reduced to a state 

 of living mummies by the effect of the poison of the mother. 

 These animals so inclosed are incapable of defending themselves, 

 but retain sufficient life to prevent decomposition, and serve for 

 the support of the larvae of the wasps. The nests, after having 

 been provisioned, are carefully closed by the mother with clay, 

 with just sufficient covering that the young insect can pierce it to 

 escape when it has undergone its last transformation. 



Certain species of Odynerinae (Zethus) appear to manifest a 

 tendency toward social habits ; they form small agglomerations 

 of nests which resemble a little the irregular nests of humble 

 bees (Bombus), but grouped yet more confusedly. But there 

 always prevails this difference between the cells formed by the 

 social and those made by the solitary Hymenoptera that the first 

 have a cylindrical inner space, while the second are rather ex- 

 tended masses which are not in regular juxtaposition, so that they 

 seem more like spheres and ellipsoids joined together, than cells 

 constructed side by side on a general plan. In other words, the 

 solitary species never seek to form a comb, although they some- 

 times form agglomerations of cells. The most part of them do 

 not construct these rough cells one upon another, but disperse 

 them into different positions. 



I. THE ANOMALIPENNES. 



The first recurrent nervure received by the second cubital cell ; 

 the second recurrent nervure received by the third cubital cell. 



I. Lip extremely lengthened, bent back under the sternum ; man- 



dibles truncated obliquely, having terminal teeth. 

 Genera: RapJtiglossa Sadsd. — Siennrjlossa Sauss. 

 Not known to be represented in America, 



II. Lip shorter ; Mandibles moderately long, sharp. 



