NO. 1438. WINGS OF THE TENTHREDINOIDEA—MavGILLIVRAY. 589 



same as is found in XipTiydria. This is an interesting example of 

 how ver}^ specialized a wing may be in one part while in others it may 

 have retained a very generalized condition. In the Lydidte (tigs. 30-43) 

 media arises in a manner similar to that just described, but the medio- 

 cubital cross-vein is alwaj's many times longer than the transverse 

 part of media and meets it soon after it separates from radius in the 

 genera Bactroceros (fig. 41), Ceplialela (fig. 42), Neurotonia (fig. 36), Lio- 

 lyda (fig. 43), and PamphUiu.i (fig. 39), while in the genera Itycorsin (fig. 

 40), Cmnolyda (fig. 38), and Lyda (fig. 37) it arises in the angle formed 

 between radius and media. It is of interest to note that in the case of 

 those genera where it arises in the angle between radius and media no 

 part of the cross-vein has migrated onto radius, but that it is attached 

 to the very base of media. In the anomalous genus Blcmticotoma (fig. 

 44) media, after separating from radius, goes ofl^ at a right angle for a 

 short distance and then turns abruptl}' toward the apex of the wing, 

 the anterior end of the cross-vein being joined to media at the point 

 where the abrupt bend is made and the posterior end, instead of join- 

 ing cubitus almost directly behind its anterior end, as in the general- 

 ized families Xyelida? and Lydidaj, has migrated along cubitus toward 

 the base of the wing and extends toward media at an angle of about 

 45°. In most Cephidi\j (figs. 93-96) media arises as in the Lydida^ and 

 the cross-vein is in a similar position, but on first examination it 

 appears to be very difl'erent. This is due to the niigration of the basal 

 end of the radial sector towai'd the radial cross-vein and the migration 

 of the radio-medial cross-vein toward the apex of the wing, in this 

 way greatly increasing the size of the cell R. 



The modifications found in the famil}^ Tenthredinida^ (figs. 45-84) 

 are a continuation of those just descril)ed. The cell R instead of 

 being a large irregular area with no two sides parallel has been trans- 

 formed into a small quadrangular cell with the opposite sides parallel. 

 Media has not changed its position materially from that found in the 

 Lydida^ and Blasticotomidie, but the medio-cul)ital cross-vein is very 

 inconstant in its location. It is usually found in a position similar to 

 that found in Blastlcotoma (fig. 44), extending at an angle of about 45'^. 

 The posterior or cubital end is fairly constant in position, but the 

 anterior end, from being attached to the base of media, as in PericUsta 

 (fig. 69), swings toward the base of the wing; in Acord/ulecera (fig. 83), 

 Bhadlnoora (fig. 7()), Lohoceras (fig. 82), Monoctenus (fig. 67), and 

 Perga (fig. 84) it is attached in the angle between radius and media; in 

 Strongylogaster (fig. 51), Stromhoceros (fig. 50), Dolerns (fig. 49), and 

 Clad! us (fig. QQ) it is attached to radius just before the angle; in 

 Macrophya (fig. 57), Pteronus (fig. *o^), Hoplocampa (tig. 61), and 

 Dlneura (fig. 63) it is attached to radius for a considerable distance 

 before the angle, and, finally, in Trlckiosoma (fig. 5t>) and Clavellaria 



