172 Scudder — Fossil Insects of North America. 



V. — The Fossil Insects of North America. 



By Samuel II. Scudder, Curator of the Museum of the Boston Society of Natural 



History, U.S. 



THE discovery of fossil insects in North America is of very recent 

 date; even now, scarcely a hundred specimens have been 

 brought to light, and they have occurred, with few exceptions, as 

 solitary individuals. The Reports of State and provincial geologists, 

 which have added so richly to our knowledge of the palaeontology of 

 North America, have hardly mentioned these fossils. As descriptions 

 of them are scattered through many publications — doubtless difficult 

 of access to English 'geologists — and as most of the specimens 

 referred to have passed under my eye, I have prepared this general 

 resume of what is known and have accompanied it with critical re- 

 marks.' 



The oldest fossil insects yet discovered in America — and, indeed, 

 in the world — consist of a few broken wings of Neuroptera, imbedded 

 in the Devonian rocks of Lancaster, New Brunswick. The locality 

 — '' Fern Ledges " — so called by Mr. C. F. Hartt, the discoverer of 

 the remains, is about a mile west of the town of Carleton, not far 

 from St. John. The rocks form a series of ledges, exposed on the 

 sea shore between high and low water marks. The beds of sand- 

 stone and shale, of which they are composed, have a seaward dip of 

 about 45° and a strike of about W. 10° N., corresponding very nearly 

 to the trend of the shore. The fossiliferous shales between the en- 

 closing sandstones are worn away by the action of the water, leaving 

 the fossils accessible in but few places. The whole deposit is of very 

 limited extent; it reaches along the shore for about three hundred 

 and twenty-five paces, exposing a thickness of strata of one hundred 

 and forty-five feet, with a width of some three hundred feet. 



Mr. Hartt has given a detailed description of these strata, from 

 which the following section, showing the position of the fossil insects, 

 is derived : — ' 



Sandstones and shales 



Calamites and obscure markings 



23 ft. 



Fine-grained, light-greenish shales 



Obscure markings 



1ft. 



Sandstones and coarse shales 



Cordaites (two sp.) and Fecopteris 



26 ft. 



" Plant Bed No. 8." 3 Fine -grained, 

 tough but fissile sandstones, rather 

 coarse shales, often of a greenish 

 cast, and, at the top, a thin layer 

 of very black shale, very rich in 

 plants— the lower portion filled 

 with remains of plants like the 

 leaves of an herbarium 



€ordaites (three sp.), AsterophyU 

 lites, Annularia, Pinnularia, Ly- 

 copodites, Cyclopteris (two sp.), 

 ]S europteris^ Hymenophyllites, Fe- 

 copteris (two sp.), Cardiocarpon 

 (three sp), and several other un- 

 determined plants. Insects : Ho- 

 mothetus fossilis, Dyscritus vetus- 

 tus, and Lithentomum Earttii 



1ft. 10 in. 



" A short account of these discoveries of Insect remains in North America was 

 given by Principal Dawson, LL.D., F.R.S., with some figures of the same in Vol. IV. 

 of the Geological Magazine, September, 1867, p. 385. 



2 See Bailey's Observations on the Geology of Southern New Brunswick. Appendix 

 A, pp. 131-141, 8vo., Frederickton, 1865. 



3 The highest in the series. I have reversed the order followed by Mr. Hartt. 



