DEVONIAN AGE. 283 



In Russia, the Devonian formation is exposed over a great extent of country. The 

 rocks are mostly marlytes and sandstones, with some laminated limestones. According 

 to Kutorga, the prevailing order is — marlytes below, then sandstones, then argillaceous 

 limestone. 



There is thus a great diversity in mineral character, and no con- 

 formity in the subdivisions of the Devonian with those in America. 

 As already explained, these subdivisions are in general due to causes 

 that have acted too locally to be often alike and synchronous in very 

 distant regions. 



H. Life. 



1. Plants. 



Europe and Britain have afforded, in addition to sea-weeds, remains 

 of plants mostly related in genera to those of the United States ; so 

 that the other continents besides America had their Ferns, Lycopods, 

 Calamites, and Conifers. Devonian plants have been reported also 

 from Queensland, Australia. 



Among the Devonian plants of Ireland, in beds that contain also remains of Coccos- 

 teus and Glyptolepis, there are Cyclopteris Hibernica Forbes, Sphenopteris Hookeri Baily, 

 S. Humphriesiana, Calamites radiatus Br., Lepidodendron Veltheimianum Sternb., Knor- 

 ria acicularis Gopp., Cyclostigma minutum Haughton, C. Kiltorkense Haughton, and 

 others. Heer has identified Calamites (Bornia) radiatus Brngt., Lepidodendron Velthei- 

 mianum, Cyclopteris Rozmeriana Gopp. (a European species near C Hibernica), Sphe- 

 nopteris Schimperi Gopp., Knorria imbricata Sternb., Cyclostigma minutum and C. Kil- 

 torkense, etc., in beds of sandstone on Bear Island (74° 30' N.), which he refers to the 

 lower part (his Ursa, stage) of the Subcarboniferous, fifteen out of the eighteen species 

 there found being known and partly wide-spread species, and several occurring in the 

 Ursa beds of the Vosges and Black Forest. In a shale, regarded as Devonian, under 

 the Subcarboniferous of Moresnet, occurs Cyclopteris Bcsmeriana, with Spirifer dis- 

 junctus Sow. 



2. Animals. 



The range of animal life was similar to that of America. A few 

 species of Europe and America were identical ; but the great majority 

 were distinct : as regards genera, the identity was very nearly com- 

 plete. 



Corals were abundant in Europe, especially Favosites and the 

 Cyathophylloid species ; and coral-reefs were forming in the Eifel and 

 some other parts. Mollusks were most abundantly represented by 

 Brachiopods, and Crustaceans by Trilobites and the little Ostracoids. 

 There were also large species of Eurypterus, Pterygotus, and allied 

 forms, some of which had the length, enormous for Crustaceans, of 

 five feet. For details respecting these Entomostracans, see Wood- 

 ward's " Memoir," published by the Paleontographical Society. 



Among Brachiopods, Spirifers were very common ; and the genus 

 Productus made its first appearance, along with others of less prom- 



