TRANSACTIONS OF SECTION D. 17 
which succeeded it, and has continued down to the present day. It is, of course, 
a perfectly trite and obvious conclusion but not the less one to be wondered at, that 
the force of heredity should thus far outlast the ebb and flow of terrestrial change 
throughout the vast period over which the geologist is our guide. 
If, however, the older Palseozoic rocks tell us nothing of the origin of the 
antenna-bearing Arthropods, what do they tell us of the history of the Myriapod 
and Hexapod Classes P 
The Myriapods are well represented in Paleeozoic strata, two species being 
found in the Devonian and no less than thirty-two in the Carboniferous, Although 
placed in an Order (Archipolypoda) separate from those of living Myriapods, these 
species are by no means primitive, and do not supply any information as to the 
steps by which the Class arose. The imperfection of the record is well seen in the 
traces of this Class ; for between the Carboniferous rocks and the Oligocene there 
are no remains of undoubted Myriapods. 
We now come to the consideration of insects, of which an adequate discussion 
would occupy a great deal too much of your time. An immense number of species 
are found in the Palzeozoic rocks, and these are considered by Scudder, the great 
authority on fossil insects, to form an Order, the Paleeodictyoptera, distinct from any 
of the existing Orders. ‘The latter, he believes; were evolved from the former in 
Mesozoic times. These views do not appear to derive support from the wonderful 
discoveries of M. Brongniart ' in the Upper Carboniferous of Commentry in the 
Department of Allier in Central France. Concerning this marvellous assemblage of 
species, arranged by their discoverer into 46 genera and 101 species, Scudder truly 
says : 
‘Our knowledge of Paleeozoic insects will have been increased three or four fold 
at a single stroke..... No former contribution in this field can in any way 
compare with it, nor even all former contributions taken together.’ * 
When we remember that the group of fossil insects, of which so much can be 
affirmed by so great an authority as Scudder, lived at one time and in a single 
locality, we cannot escape the conclusion that the insect fauna of the habitable 
earth during the whole Palseozoic period was of immense importance and variety. 
Our knowledge of this single group of species is largely due to the accident that coal- 
mining in Commentry is carried on in the open air. 
Now, these abundant remains of insects, so far from upholding the view that 
the existing orders had not been developed in Palzeozoic times, are all arranged by 
Brongniart in four out of the nine Orders into which insects are usually divided, 
viz. the Orthoptera, Neuroptera, Thysanoptera, and Homoptera. The importance 
of the discovery is well seen in the Neuroptera, the whole known Palxozoic 
fauna of this Order being divided into 45 genera and 99 species, of which 33 
and 72 respectively have been found at Commentry. 
Although the Carboniferous insects of Commentry are placed in new families, 
some of them come wonderfully near those into which existing insects are classified, 
and obviously form the precursors of these. This is true ofthe Blattide, Phasmide, 
Acridiidee, and Locustide among the Orthoptera, the Perlide among the 
Neuroptera, and the Fulgoride among the Homoptera. The differences which 
separate these existing families from their Carboniferous ancestors are most 
interesting and instructive. Thus the Carboniferous cockroaches possessed ovi- 
positors, and probably laid their eggs one at a time, while ours are either vivi- 
parous or lay their eggs in a capsule. The Protophasmidz resemble living species 
in the form of the head, antenne, legs, and body; but while our species are either 
wingless or, with the exception of the female Phyllide, have the anterior pair 
reduced to tegmina, useless for flight, those of Palaeozoic times possessed four well- 
developed wings. The forms representing locusts and grasshoppers (Palewacridiide) 
possessed long slender antennz like the green grasshoppers (Locustide), from 
which the Acridiidz are now distinguished by their short antenne. The diver- 
gence and specialisation which is thus shown is amazingly small in amount. In 
1 Charles Brongniart.—‘ Recherches pour servir 4 l’Histoire des Insectes fossiles 
des temps primaires, précédées d’une Etude sur la nervation des ailes des Insectes.’ 
1894. 2 §. H. Scudder, Am. Jowrn. Soi., vol. xlvii. February 1894. Art, viii. 
