

DISTRIBUTION 341 



outcrops between tide-marks; these forms, though few, are of extraor- 

 dinary interest, as will be seen. 



For Carboniferous species, Commentry in France is a rioted locality, 

 through the admirable researches of Brongniart, who described from 

 there 97 species of 48 genera, representing 12 families or higher groups, 

 10 of which are regarded as extinct; without including many hundred 

 specimens of cockroaches which he found but did not study. In this 

 country many species have been found in the coal fields of Illinois, 

 Nova Scotia, Rhode Island, Pennsylvania and Ohio. 



Many fine fossils of the Jurassic period have been found in the litho- 

 graphic limestones of Bavaria; 143 species from the Lias- four fifths of 

 them beetles were studied by Heer. 



The Tertiary period has furnished the majority of fossil specimens. 

 To the Oligocene belong the amber insects, of which 900 species are 

 known from Baltic amber alone, and to the same epoch are ascribed the 

 deposits of Florissant and White River in Colorado and of Green River, 

 Wyoming. These localities the richest in the world have been made 

 famous by the monumental works of Scudder. At Florissant there is an 

 extinct lake, in the bed of which, entombed in shales derived from vol- 

 canic sand and ash, the remains of insects are found in astonishing pro- 

 fusion. For Miocene forms, of which 1,550 European species are 

 known, the (Eningen beds of Bavaria are celebrated as having furnished 

 844 species, described by the illustrious Heer. 



Pleistocene species are supplied by the peats of France and Europe, 

 the lignites of Bavaria, and the inter glacial clays of Switzerland and 

 Ontario, Canada. 



Silurian and Devonian. The oldest fossil insect known consists of 

 a single hemipterous wing, Protocimex, from 

 the Lower Silurian of Sweden. Next in age 

 .comes a wing, Palceoblattina (Fig. 301), of 

 doubtful position, 1 from the Middle Silurian 

 of France. Following these are six specimens 



of as many remarkable species from the Devon- * size -~ After 



ian shales of New Brunswick. The specimens, 



to be sure, are nothing but broken wings, yet these few fragments, 

 interpreted by Dr. Scudder, are rich in meaning. All are neuropteroid, 

 but they cannot be classified satisfactorily with recent forms on account 

 of being highly synthetic in structure. Thus Platephemera antiqua (Fig. 



1 There is some evidence, it should be said, that this species is not an insect. Handlirsch 

 denies also that Protocimex is an insect. 



