Dawson — On Palceozoic Insects. 387 



those of the Carboniferous period. They were all Neuropterous 

 insects, and allied to the Ephemeras. It is interesting, however, to 

 observe that, like many other ancient animals, they show a remark- 

 able union of characters now found in distinct orders of insects ; or 

 constitute syntJietic types, as they have been termed. Nothing of this 

 kind is more curious than the apparent existence of a stridulating or 

 musical apparatus like that of the cricket, in an insect otherwise 

 allied to the Neuroptera. This structure also, if rightly interpreted 

 by Mr. Scudder, introduces us to the sounds of the Devonian woods, 

 bringing before our imagination the trill and hum of insect life that 

 enlivened the solitudes of these strange old forests. Mr. Scudder has 

 kindly furnished descriptions of these insects as follows : — 



PlatepJiemera antiqua, Scudder (Plate XVII. Fig. 2). — The direction 

 of the principal nervures in this insect convinces me that it belongs 

 to the Ephemerina, though I have never seen in living Epliemerina so 

 much reticulation in the anal area as exists here — so, too, the mode 

 in which the intercalary nervules arise is somewhat peculiar. It is a 

 gigantic species, for it must have measured five inches in expanse of 

 wings — the fragment is a portion of an upper wing. 



EomotJietus fossilis, Scudder (Plate XVII. Fig. 3). — At first sight 

 the neuration of the wings of this insect seem to agree sufficiently 

 with the Sialina to warrant our placing it in that family ; but it is 

 very interesting to find, in addition to minor peculiarities, that near 

 the base of the wing, between the two middle veins, there is a heavy 

 cross -vein from which new prominent veins take their rise ; this is 

 characteristic of the Odonata, and of that family only. We have, 

 therefore a new family representing a synthetic type which combines 

 the features of structure now found in the Odonata and Sialina, very- 

 distant members of the Neuroptera. The fragment is sufficiently 

 preserved to show the direction, extent, and mode of branching of 

 nearly every principal nervure. It is evidently a portion of an 

 upper wing ; the insect measured not far from three and a half inches 

 in expanse of wings. 



Liihentomum Harttii, Scudder (Plate XVII., Fig. 4). — This was 

 the first specimen discovered by Mr. C F. Hartt. I have therefore 

 named it after him. Apparently it does not belong to any family of 

 Neuroptera represented among living forms. It agrees more closely 

 with the family Hemeristina, which I founded upon a fossil insect 

 discovered in Illinois, than it does with any other ; but it is quite 

 distinct from that, both in the mode of division of the nervures and 

 in the peculiar cross-veining. The fragment which Mr. Hartt dis- 

 covered is very imperfect ; but, fortunately, preserves the most 

 important part of the wing. I am inclined to think that it was a 

 lower wing. The insect probably measured three and a half inches 

 in expanse of wing. 



Xenoneura antiquorum, Scudder (Plate XVII., Fig. 5). — Although 

 in this fragment we see only the basal half or third of a wing, the 

 peculiar mode of venation shows that the insect cannot belong to 

 any known family of Neuroptera living or fossil ; yet it is evidently 

 a Neuropterous insect. In addition to its other peculiarities there is 



