Scudder — Fossil Insects of North America. 175 



who refer this deposit to the Devonian, for several species of plants 

 are stated to be common to this formation and to the Carboniferous. 



In evidence of the Devonian age of the fossils, we have Dr. 

 Dawson's admirable papers upon the plant remains of these beds, 

 given in the Quarterly Journal of the Geological Society of Lon- 

 don for November, 1862, and November, 1863. The rocks are 

 referred by that distinguished authority to the Chemung and 

 Portage group of the New York geologists. Furthermore, the 

 group of rocks to which this plant-bearing series of shales belongs, 

 underlies unconformably beds whose Lower Carboniferous age is 

 unquestionable. The Cordaite shales of Lancaster rest directly and 

 conformably upon the Dadoxylon Sandstone,^ but as the shales are the 

 highest members of the series of rocks lying on the westerly side of 

 Courtney Bay, we must cross to the eastward to discover the super- 

 incumbent formations. 



The Dadoxylon Sandstone is composed of rocks, easily traceable 

 throughout the province by their uniformity.^ The overlying 

 Cordaite shales are usually rich in metalliferous deposits, and have 

 been very carefully explored : upon them rest conformably, more 

 than 1800 feet of rocks, described by Dr. Dawson^ as •' dark red 

 and greenish shales ; flaggy sandstone sand grits ; coarse angular 

 conglomerate." They are called the Mispeck group, and considered 

 the uppermost member of the Devonian series. Now these latter 

 rocks are covered unconformably by conglomerates, which form the 

 very base of the Carboniferous formation.^ Special instances may 

 be cited in the neighbourhood of Eed Head^ and at Martin's Head® 



Great interest attaches to the insects themselves : six specimens 

 in all,'' each differing from the others, were discovered by Mr. Hartt. 

 They are all Neuroptera. 



Gerephemera simplex is represented by a slight fragment on the 

 tip of a wing ; the wing must have been large and broad ; the veins, 

 distant, weak, and simple. It is apparently a member of the family 

 of Ephemerina. 



Platephemera antiqua belongs to the same family, although its 

 neuration is quite peculiar, and I have never seen in a Ephemerid 

 so much reticulation in the anal area; the intercalary nervules, 

 which, in Ephemerina, generally originate independently, arise here 

 from a bent cross-vein, much as in Odonata. It is a gigantic species, 



1 Hartt, in Bailey's Geology of Southern New Brunswick, p. 134. 



3 Bailey. Geology of Southern New Brunswick, p. 55. 



3 Quart. Journ. Geol. Soc. Lond., 1862, p. 302. 



* Bailey. Geology of Southern New Brunswick, pp. 77 and 80. Dawson. Quart. 

 Journ. Geol. Soc, Lond., 1865, p. 98. 



5 Quart. Journ. Geol. Soc, Lond., 1862, p. 302. 



« Bailey. Geology of Southern New Brunswick, p. 96. I have been particular 

 in my references to authorities, because if the determination of these rocks prove 

 correct, a whole class of animals, hitherto known as early as the Carboniferous, are 

 referred at once to a previous epoch. 



' A brief notice of these remains was given in Professor Bailey's Geology of 

 Southern New Brunswick, published in 1865, and short descriptions and figures have 

 been furnished to Dr. Dawson for the new edition of his Acadian Geology. See also 

 Sill. Amer. Journ. Sc. and Arts [2] xliv., p. 116: and Geol. Mag., 1867, Vol. IV., 

 p. 385, PL XVII. 



