THE PENNSYLVANIAN PERIOD. 



611 



species of Carboniferous insects from American deposits and a com- 

 parable number from the European, previous to 1891, with constant 

 additions since, indicates the great development of this class. They 



Fig. 284. — Carboniferous terrestrial and fresh-water Life. Plants: a, Callip- 

 teridium mansfieldi Lesq., b and c, Callipteridium membranaceum Lesq., two species 

 of ferns. Land shells: d, Zonites priscus Carp., e, Pupa vermilionensis Bradley. 

 These land snails have been referred to genera living at the present time, and 

 although this reference may eventually prove to be incorrect, they are at least 

 close relatives of recent genera. Insects, etc.: /, Euphoberia armigera M. and W., 

 a Carboniferous myriapod or thousand-legged worm; g, Eoscorpius carbonarius, 

 M and W., a scorpion very similar in type to living forms; h, Arthrolycosa antiqua 

 Harger, a spider more primitive than recent forms as seen by the segmentation 

 of the abdomen; i, Progonoblattina Columbiana Scudd , one of the allies of the 

 modern cockroaches which were the most conspicuous members of the Car- 

 boniferous insect fauna. Crustacea: j, Anthrapalozmon gracilis M. and W., k, 

 Pal&ocaris typus M. and W., two types of crustaceans found in the Mazon Creek 

 nodules; I, Prestwichia danw M. and W., one of the early allies of the modern 

 horse-shoe crab. (Weller.) 



were still, for the most part, of the rather primitive synthetic types, 

 often uniting characters not now found in the same order, and some- 

 times embracing strange combinations, as a neuropterous wing on an 

 orthopterous body; but advancing differentiation was already mani- 

 fested. The orthopterous group, embracing cockroaches (Fig. 284, i), 

 locusts, crickets, and walking-sticks, were greatly in the lead, followed 



