448 GEOLOGY. 



Other continents. — The Devonian system has a wide distribution 

 in Siberia and China, where its faunal relations are with northern 

 Europe. It is known in Asia Minor, Persia, and northwestern India 

 (Himalayas and eastern Tibet). It perhaps has wide distribution 

 in North Africa (Atlas mountains, Sahara), in South Africa (Cape 

 Colony), and in the Falkland islands. Glacial beds of Devonian age 

 have been reported recently from South Africa. 1 The fauna of the South 

 African Devonian has South American affinities. The system has con- 

 siderable development in South America, and carries an indigenous 

 fauna akin to the Hamilton fauna of North America. So far as identified 

 in this continent, the Devonian beds are referable to the upper part of 

 the Lower Devonian, and to the lower part of the Middle. 2 The system 

 attains a thickness of 10,000 feet in New South Wales, 3 Australia, and 

 has been recognized in Victoria. With the Middle Devonian sedi- 

 mentary formations of Victoria, f elsitic lavas and tuffs are associated. 

 Devonian(?) rocks are the oldest known formations of the North Island, 

 New Zealand, and attain great thickness — 7000 to 10,000 feet 3 — in the 

 South Island. Kayser 4 recognizes two great Devonian provinces, viz., 

 t-ie Eurasian, including a large part of north and central Asia, and prob- 

 ably extending to Manitoba, and the American, including much of the 

 United States, South America, and South Africa. 



DEVONIAN LIFE, 



I. The Marine Faunas. 



General faunal evolutions. — It may be recalled that the early 

 marine faunas of the Cambrian period were interpreted as regional 

 or provincial in type, but were found to merge into a more general 

 type toward the close of the period. The Ordovician fauna was regarded 

 as really little more than a continuation and expansion of the Cam- 

 brian fauna and as singularly general at its climax. After a repres- 

 sional interval, the Silurian fauna seems to have developed into a 

 similar cosmopolitan type, followed by a restrictive evolution. It is 

 now to be noted that the Devonian period, in America at least, brought 



iSchwarz, Jour. Geol., Vol. XIV, p. 683, 1906. 



2 Kayser, Geologische Formationskunde. 3 Geikie, op. cit., p. 999. 



4 Idem, Zweite Auflage,p. 154. Other and minor faunal provinces are defined by 

 Lebenden, Mem. du Comite geologica, XVII, No. 2, pp. i-x, and Barrois. 



