lis PIMPLINE ICHNEUMONIDAE 



extending backward from the middle of the areolet to near 

 the outer end of the subdiscoidal. The recurrent nervures 

 form the inner and outer margin of the third discoidal cell, with 

 the cubital forming its front and the subdiscoidal joining 

 its hinder borders. The subdiscoidal nervure forms the front 

 margin of the first apical cell, while its inner margin is formed 

 by the outer part of the discoidal nervure and behind it is bounded 

 by a small portion of the anal nervure, the outer part of the 

 internal margin, the anal angle and the hinder portion of the 

 outer margin of the wing. Between the cubital and subdiscoidal 

 nervures and extending from the second recurrent nervure to 

 the outer margin, lies the second apical cell. The frenal fold 

 is near the outer end of the anal cell. 



The writer is inclined to agree with Snodgrass^ in his inter- 

 pretation of the venation of an Ichneumonid wing, as indicated 

 by his Figure 76, rather than with that used by Cresson.^ 



The two systems agree in the main, the points of disagreement 

 being the discoidal and first recurrent nervures. According to 

 the system used by Cresson, the first recurrent nervure (1.) sep- 

 arates the two parts of the discoidal nervure (j.). 



In the fore wing of Mellinus which Cresson ^ uses as a typical 

 Hymenopteron wing, the two recurrent nervures are very distinct 

 and there can be no question raised as to their identity. Here, 

 the first recurrent nervure extends from the discoidal nervure 

 (j.) to the cubital nervure (k.). In the fore wing of Megarhyssa 

 lunator, the cubital nervure at its anterior end is but an abbre- 

 viated stump. According to Snodgrass, the vein from (j.) to 

 (k.) forms the first recurrent nervure (No. 16, fig. 76). This agrees 

 with the condition found in Mellinus and seems to be a more 

 plausible explanation than calling it part of the discoidal nervure 

 (1.) with parts of the latter on either side of it (j.). If Snod- 

 grass's interpretation is accepted, then the discoidal nervure 

 remains as such from beginning to end. 



In Mellinus the first transverse cubital nervure extends for- 

 ward from the point where the first recurrent nervure joins the 

 cubital, to the marginal or radial nervure, but in the fore wing 



5 'Thorax of Hymenoptera,' 1910, pi. G, fig. 76. 



^ Synopsis of the Hymenoptera of North America, p. 38, fig. 9. 



^ Synopsis of the Hymenoptera of North America, p. 5, fig. 4. 



