102 



THE PALEONTOLOGICAL DATA 



A second species from the same formation is Paolia Gurleyi (Fig. 99). 

 This differs from the preceding species in the smaller nimiber of the acces- 

 sory branches of media. 



A study of these three wings, the oldest of the known insect remains 

 found in the United States, leads to the conclusion that the primitive 



/?; 



-Paolia Gurleyi (After Handlirsch). 



Fig. 98. — Paolia vettista (After Handlirsch). 



arrangement of the principal branches of media was that indicated in the 

 diagram, by Comstock and Needham, of the hypothetical primitive type. 

 It also shows that in these ancient insects the four principal branches of 

 media bore a variable ntimber of ac- 

 cessory veins, near the margin of the 

 wing. The lack of uniformity in the 

 number and position of these acces- 

 sory veins parallels the conditions Bi^ 

 that exist in recent insects with 

 accessory veins; where the number 

 and position of the accessory veins p- „„ . 

 is of hardly more than specific value. 



The Alabama specimen, which is believed to be nearly contempor- 

 aneous with the two just described, is Campteroneura reticulata (Fig. 100). 

 It is doubtful if the fragment preserved contains any part of the media; 



but even if it does, there is 



not enough of this vein to 

 enable us to determine the 

 nature of the branching 

 of it. 



Another fragment of a 

 wing from Alabama is sup- 

 posed to be of a slightly 

 more recent time; this is 

 the Bathytaptus falcipennis 

 (Fig. 1 01). Only part of 

 media is preserved, but enough to show that it was not of the isolated 

 front branch type. 



Fig. 100. — Campteroneura reticulata (After 

 Handlirsch). 



