WALTER^ CLASPING ORGANS IN HYM^NOPTERA 83 



ber they stand at small, equal intervals. More or less robust mar- 

 ginal bristles are always present. 



Thirty-four species were examined, among them in greater num- 

 bers Pimpla instigator Grav., Rhyssa persuasoria Grav., Ichneumon 

 fusorhts and luctatoriiis L. 



IV. Braconidje 



The distal hooks are weak, slender, very slightly curved, and 

 placed upon the costal vein a little behind the place where it joins the 

 margin (pi. vn, fig. 8). The subbasal hooks are difficult to distin- 

 guish from the marginal bristles, which are more numerous than in 

 the Cynipidse. 



Three species were examined. 



V. Proctotrupid.e 



Two extremely slender, very slightly curved distal hooks are pres- 

 ent. These are placed in the middle of the anterior margin of the 

 hind wing, in which, only at the base, an indication of a costal vein 

 can be detected (pi. vii, fig. 2). There are sparse marginal bristles, 

 but no subbasal hooks. 



One species was examined. 



VI. Chrysidid.e 



The distal hooks are well developed, generally very numerous, and 

 placed upon the costal vein behind the insertion of the cross-vein. 



Subbasal hooks are always present. They are well developed and 

 placed at irregular intervals near the base of the wing (pi. vm, fig. 

 17). Marginal bristles are always present before and behind the 

 series of subbasal hooks ; they are stoutest at the base of the wing. 



Three species were examined. 



VII. Formichls: 



The distal hooks are very slender, delicate, and slightly curved. 

 They are placed upon the costal vein, the series beginning behind the 

 insertion of the cross-vein (pi. vn, fig. 7). Subbasal hooks are want- 

 ing. The marginal bristles are extremely small and thin. 



Seven species were examined, among them, in a larger number of 

 specimens, Formica rufa L., Camponotus ligniperdus Mayr., and 

 Lasins Uavus Mayr. 



VIII. Fossores 



In this family such a diversity prevails that it is hardly possible to 

 give even an approximate characterization. The distal hooks, in 

 form and arrangement, sometimes resemble those of the Ichneu- 



