suBPHYLUM III INSECTA 821 



of various primitive groups are known from the Permian of Russia, Germany, West 

 Virginia, Kansas and Colorado, so that on the whole we are fairly well acquainted 

 with these heterometabolic ancestors of modern orders. Unfortunately, however, very 

 little evidence is forthcoming from the Trias, during which era the transition from 

 the heterometabolic to the holometabolic stage probably took place. Nevertheless, 

 a few fossil remains are known from the Trias of Sweden, Germany, Austria, 

 Switzerland and China. Numerous tracks of supposed Insects, and also what are 

 believed to be the aquatic larvae of an alder-fly {Mormolucoides articulatus Hitchcock), 

 occur in the dark shales of the Connecticut Valley Trias. 



A fairly rich insect fauna has been discovered in the Lias of Sehambelen in 

 Aargau, Switzerland, Dobbertin in Mecklenburg, Brunswick, "Weyer in Austria, and 

 several localities in Somerset, Gloucestershire and Yorkshire, England. A few 

 remains are preserved in the Stonesfield Slate near Oxford, England, and in strata 

 of the same age in Siberia ; and a considerable number of sjiecies occurs in ihe Purbeck 

 of the southwestern counties of England. Richest of all, however, is the Upper 

 Jurassic insect fauna, especially that which is found in the Lithographic Stone 

 (Kimmeridgian) of Bavaria. Contrariwise, the Cretaceous is markedly deficient in 

 information respecting this group of invertebrates. 



Tertiary sediments have yielded an enormous quantity of well-preserved insect 

 remains. Among the more important localities that have furnished material of this 

 nature, mostly of mid-Tertiary age, may be mentioned the freshwater deposits of 

 Florissant, Colorado, Aix-en-Provence, Oeningen on Lake Constance in Baden, Radoboj 

 in Croatia, Rott (Upper Oligocene lignite) near Bonn on the Rhine, Brunnstatt in 

 Alsace, Sieblos in Bavaria, Bilin in Bohemia and Gabbro in Tuscany ; also the 

 Oligocene strata at Quesnel in British Columbia, and the Green River Eocene of 

 AVyoming, western Colorado and eastern Utah. But by far the largest and most 

 varied assemblage of Tertiary insect remains is obtained from Oligocene amber in 

 East Prussia. 



Finally, in the Pleistocene, the interglacial clays of Switzerland, German}^ and 

 Ontario, the jDeats of northern France and England, the ozokerite of Galicia, and the 

 lignites of Husbach in Bavaria, deserve mention as localities which have furnished 

 fossil insect remains. In the accomj^anying table is indicated the geological range of 

 the different orders of Insects. 



[The preceding chapter on Insecta has been prepared especially for the present work by 

 Professor Anton Handlirscli, of the Imperial Museum of Natural History at Vienna. A 

 few minor emendations have been suggested by Dr. W. J. Holland, Director of the Carnegie 

 Museum at Pittsburgh, and others by Professor T. D. A. Cockerel], of the University of 

 Colorado. — Editok. 1 



