INSECTS OP NEW BRUNSWICK, H 



If we look to other early types for species akin to this we shall find a whole group of 

 carboniferous insects with reticulated wings, to which this is evidently related. To this 

 belong those forms to which the generic names Dictyoneura and Breyeria have been given 

 in the old world, and Paolia and Haplophlebium in the new. Several new forms, as yet 

 unpublished, are known to me from the American carboniferous rocks. In all these 

 genera, but especially in Dictyoneura and Haplophlebium (which perhaps should not be 

 separated from each other), the wing is very much larger and slenderer (like a dragon-fly's 

 wing) than the fragment of this devonian wing will allow us to suppose it to be. As in 

 these wings, the mediastinal vein is present, and usually runs into the marginal at some 

 distance from the tip of the wing, and the general relation of the principal veins is sim- 

 ilar in all ; in none of the others, however, do we find so distinct a meshwork of sub- 

 ordinate veins, nor can they be resolved as here into sets depending from the two prin- 

 cipal branches of the externomedian vein. So that while a general similarity of structure 

 may be conceded, tliere is no occasion for considering the insects as closely affiliated. 



The distinction between Platephemera and Gerephemera will be pointed out in treating 

 of the latter insect. 



This insect comes from plantrbed No. 7 of Professor Hartt, and was the only insect 

 found at that horizon. 



In his " Monograph on the Ephemeridae,"^ Rev. Mr. Eaton treats of the fossil species 

 which have been referred by one and another author to this family, in a very summary 

 manner,^ asserting that : " when a fossil comprises only a fragment, or even a complete wing 

 of an Ephemerid, it is hardly possible to determine the genus, and impossible to assert the 

 species. The utmost that can be learned from such a specimen is the approximate 

 relations of the insect. Neuration by itself is not sufficient to define the species or even 

 the genera of recent Ephemeridae." 



While we should not wish to deny the claims of Mr. Eaton to a profound knowledge of 

 the structure of the Ephemeridae, we venture to doubt if he would assert that there are 

 not features in the wing structure of some genera not found in others, and which are, 

 therefore, in so far characteristic of those genera; and it might be worth while to consider 

 whether a careful study of such difierences would not reveal some further differences 

 not discernible upon a cursory examination. One should be slow to hazard sweeping 

 statements of a negative character; and after all, it may be enquired, what more is desired, 

 or at least expected, than " the approximate- relations of an insect " found fossil in the 

 older rocks. That is precisely the aim of palaeontology the world over ; and those who 

 discourage efforts to discover these relations are shnply bidding us close one of the vol- 

 umes of the book of life, quite as valuable as that they study. 



In further comments in the same place, Mr. Eaton asserts of the insects of the Devo- 

 nian discussed in this paper, that 'Hhey have all been regarded as allies of the Ephemer- 



1 Trans Entom Soc. Lond., 1871, 38-40. toward their authors. In the three pages he devotes to this 



2 The manner in which Mr. Eaton has confounded names topic, Dyscritus is twice given as " Dyscntms"; artioulatus 

 in this section of his work is pretty fair evidence that he twice as " antiqaorum"; occidentahs once as " Brownsoni "; 

 has not given the papers he quotes that close attention Bronsoni twice a« "Brownsoni ; Dana twice as Scud- 

 which would entitle him to use the language of ridicule der" ; Scudder six times a. "Dawson. 



