based on the principle of Cephalization.—Insects. 33 
grand divisions, lead off apparently in geological time the Insects 
of the globe—the Neuropters the pteroprosthenic, and the Or- 
being among Carboniferous species,) and possibly also Coleopters. 
Nothing is yet known of ancient Thysanures, although it is 
probable they were in existence at the same time. 
e should expect also from the association of the Neuropters 
and Orthopters in the same Carboniferous fauna that there 
would be examples of intermediate types between these tribes, 
that is, those which, while related fundamentally to one of the 
two tribes, presents some characteristics of the other; for in 
this way the striking harmony in the flora or fauna of an age in 
eological history was often produced,—as, for example, in the 
and-vegetation of the Carboniferous era, which embraced com- 
mon Acrogens (Ferns) and Gymnosperms; and besides these, 
fh ; 
* The Orthopterous features among Neuropters appear to be modifications of 
under the types in this group which have been already mentioned, especially 
the Lepidopteroid, and not indications of a distinct type of Orthopteroid ; 
a fossil ies re and also the modern Mantispids, are true Plani- 
ians in their wings and in their other characteristics of special im : 
hey properly constitute an Orthopteroid group in this be. 
Am. Jour. Sct.—Srcoxp Sexims, Vou. XXXVII, No. 109.—Jan., 1864. 
5 
