64 THE NORTHERN MICROSCOPIST. 
writes : “The earliest known insects were brought to light in 1865, 
in the Devonian strata of St. John’s, New Brunswick, and are 
referred by Mr. Scudder to four species of Neuroptera. One of 
them is a gigantic Ephemera, and measured five inches in expanse 
of wing.” Dr. Dawson, of McGill College, Montreal, in a work 
on the ‘‘ Geology of Nova Scotia,” describes the wing of the genus 
Haplophlebium, found in the carboniferous strata, and on the 
authority of Mr. Scudder pronounces it to belong to a gigantic 
Ephemerid that must have measured seven inches across the wings. 
He gives us a graphic picture of the swarms of the Ephemeridee of 
that remote period, as they ‘ would flit in millions over the quiet. — 
waters and through the dense thickets of the coal swamps.” 
Another specimen, the Xenoneura antiquorum, has been described 
as having a stridulating apparatus, and representing a synthetic type 
of insects, allied to the Ephemeridz and the Locusts. Various 
authors have ascribed fossil specimens of Neuroptera to sixteen 
genera of ancient Ephemeride, in some instances from obscure 
fragments of the wing only. The Rev. A. E. Eaton, who has in- 
vestigated the merits of this question, is of opinion that only three 
fossil species can be pronounced to belong to this family, of which 
the oldest known fossil was found in Bavaria, in the Solenhofen 
slate, which Sir Charles Lyell places, in reference to its position in 
geologic time, between the Kimmeridge Clay and the Coral Rag, 
in the Oolitic series of rocks. This fossil is in the British Museum. 
It represents a portion of a wing well reticulated, somewhat in the 
manner of the anterior wing of the common May-fly. Specimens 
of extinct species of the family have been found in Stettin amber, 
differing only slightly from existing forms. 
There is no doubt that those insects, the larvz of which are 
chiefly aquatic, viz., those of the orders Neuroptera and Orthoptera, 
are represented by the earliest fossil forms, their remains having 
been found in the Devonian rocks; whereas the next order in 
point of antiquity, the Coleoptera, are not found in strata earlier 
than the coal measures. This consideration led Sir John Lubbock, 
after investigating the development of the aquatic form of Cloéon, 
to propound an ingenious theory of the origin of the wings of in- 
sects, which will be found in a small volume of the “Nature 
Series.” You will recollect that Cloéon has external branchial 
plates on the first seven segments of the abdomen, which <are 
gradually acquired during growth, the larva being born without 
branchize, and the sixanterior pairs being at first single and after- 
wards double plates. He says that insects may originally have 
come from a type like the larva of Cloéon in form, but without 
legs, and having a pair of single plates on each segment of the 
body, serving both for respiration and locomotion, Those plates 
placed near the centre of gravity “‘ would serve the most efficiently 

