THE DEVONIAN PERIOD. 495 



some at least of the Devonian insects were terrestrial vegetable feeders 

 is perhaps indicated by Scudder's identification of a stridulating call- 

 organ attached to the wing of Xenoneura antiquorum which implies 

 not only an arboreal habit but an advanced evolution of the hearing 

 organs. Fig. 227 illustrates the wing structure of this species, and 

 shows, imperfectly, the supposed stridulating organ. As cockroaches 

 had appeared in the Silurian, they also were probably present. 



Other terrestrial forms. — Myriapods, arachnoids, and a scorpion 

 are reported from plant-beds in New Brunswick, referred by Dawson 

 and others to the Devonian. Myriapods were present in England 

 in at least two genera, according to Peach. 1 Terrestrial mollusks 

 are also reported from New Brunswick. 



1 Proc. Roy. Phys. Soc. Edin., Vol. VII, 1882, p. 179. 



