S. H. SCUDDER ON THE WINGS OF FOSSIL NEUROPTERA. 173 



VI. An Inquiry into the Zoological Relations of the first discovered traces of Fossil Neuropterous 

 Insects in North America ; with Remarks on the difference of structure on the Wings of liv- 

 ing Neuroptera. Bg Samuel H. Scudder. 



Read January 18, 1865. 



IN the January number of Silliman's "American Journal of Science" for 1864, (vol. 

 xxxvn., page 34,) Prof. J. D. Dana announced the discovery for the first time in North 

 America of the fossil remains of Neuropterous insects. They were found in flattened iron- 

 stone concretions, which occurred in the carboniferous beds at Morris, Illinois, in company 

 with various coal-plants and amphipod crustaceans. Two specimens only had fallen under 

 his observation, which, in the Journal referred to, in an article entitled "On Fossil Insects 

 from the Carboniferous Formation in Illinois," he has figured upon wood and briefly described 

 under the names of Miamia Bronsoni, and Hemeristia occidentalis, the former after the name 

 of the original discoverer of these important remains. 



Through the repeated courtesy of Professor Dana, I have been permitted as long an ex- 

 amination as I desired of these interesting fossils, the results of which, and the comparisons 

 I have incidentally instituted with allied groups of living insects, 1 I have now the honor to 

 lay before the Society. 



The specimens imbedded in these stones exhibit the insects in the natural attitude of 

 repose, which, as in many other Neuroptera, is with the wings overlapping one another 

 above the abdomen ; in those Neuroptera which close their wings in this manner the right 

 upper wing overlaps the left upper wing (or the left overlaps the right), while that again 

 overlaps the right under wing, and this the left under wing ; the result is that in certain 

 places we have actually in a cross-section four thicknesses of wing with their accompany- 

 ing nervures, which last, if of sufficient thickness and strength to give an impression through 

 these four thicknesses, when compressed between layers of mud, would in a case like that 

 of Hemeristia, where the cross-veins are quite heavy and numerous, present an almost in- 

 extricable network of veins, and render it a very difficult task to determine the neuration 

 of any one of them. In Miamia the nervures are feeble, though the wing-tissue is appar- 

 ently correspondingly delicate ; and the wings not overlapping one another so completely 

 as in Hemeristia, it is not so difficult a task to determine to which win"- different nervures be- 

 long; yet were it not for the general similarity of the neuration in the upper and under 

 wings in this sub-order, it would even here be a perplexing matter. In Miamia the abdomen 

 is preserved, and the nervures crossing it leave no room for doubt that the insect is viewed 

 from above ; but in the specimen of Hemeristia we have the additional disadvantage that 

 we cannot tell which surface we view otherwise than by the structure and relations of the 

 wings themselves, which besides are but fragmentary, and exhibit in continuity but a small 

 portion of the outer margin of a single wing and the inner border of none at all, the base 

 and apex also being absent. We have then in Hemeristia — given the central j)ortion only of 

 four wings, completely overlapping one another, unusually charged with cross-veins reunit- 

 ing the branches in every part, with no external means of deciding whether the upper or 

 under surface is presented to the eye, to determine what is the exact structure of each wing. 



1 I would here express my obligations to my friend Mr. P. use freely bis extensive and varied collection of Neuroptera, 

 R. Ubler, for tbe kindness witb wbicb he bas permitted me to containing many forms otherwise quite unknown to me. 



