710 APPENDIX. 



the wings appear as little bags hanging down the sides, just 

 under the skin. The number of main tracheae in the wing 

 appears from one of Landois' figures to be six. Hence, as we 

 have before suspected, this is probably the typical number of 

 veins in the wings of all insects, though usually but five are 

 readily made out. 



A NEW FOSSIL CARBONIFEROUS INSECT. Mr. S. I. Smith 

 contributes to the "American Journal of Science" a descrip- 

 tion of the fore wing of Paolia vetusta from near Paoli, Indi- 

 ana. The wing (Fig. 663) is 2.54 inches in length and about 

 .85 inch wide. The venation is remarkable for the number of 

 slender branchlets which the veins throw off towards the poste- 

 rior border and the tip of the wing. The great care with 

 which the specimen has been drawn and engraved obviates the 

 necessity of farther description. Mr. Smith remarks that 



Fig. 663. 



Wing of Paolia vetusta. 



"this wing differs so much in neuration from any family of 

 recent insects, that it is difficult to point out any near affinity 

 with living forms, although it shows some points of resem- 

 blance to several families of Neuroptera, and especially to the 

 Ephemerids." To Hemeristia and Miamia, he adds, " it shows 

 more resemblance, but still differs more from either of these 

 genera, which are considered distinct families by Mr. Scudder, 

 than they do from each other. It seems still more allied to 

 Dictyoneura libelluloides of Goldenberg, Prof. Hagen consider- 

 ing it, with Eugereon Bockingii Dohrn, as a species of this 

 genus. " In both Dictyoneura and Eugereon, as figured, the 

 wings have considerable resemblance to the specimen from 

 Indiana, but in neither o them are the nervures so numerously 



