NO. I CAMBRIAN FAUNAS OF EASTERN ASIA 37 



nent and the lesser series on the Asiatic continent, described by 

 WilHs ^ as the Wu-t'ai and the Hu-t'o systems. 



In speaking- of the rocks of the Hu-t'o system he says : 



All of the rocks of the Hu-t'o system are sedimentary strata; conglom- 

 erate; quartzite, shale, and limestone, which resemble the unmetamorphosed 

 Paleozoic rocks more nearly than they do the Wu-t'ai schists. The physical 

 events which intervened between the close of the Wu-t'ai period and the 

 beginning of the Hu-t'o involved greater changes and probably longer time 

 than those which occurred after the Hu-t'o and before the Sinian; but the 

 presence of a rich fauna in the Sinian seas distinguishes that period from the 

 preceding time, during which the life forms, though probably numerous, did 

 not generally become fossil. The nearest relations of the Hu-t'o system are 

 with the Belt terrane of Montana (in America), and it is probable that pre- 

 Cambrian fossils ^ such as have been found in the Belt may eventually be 

 discovered in the Hu-t'o.^ 



In the above-quoted paragraph Doctor WilHs unconsciously gives 

 a strong argument for the non-marine origin of the rocks of the 

 Hu-t'o system when he says that the presence of a rich fauna in the 

 Sinian seas distinguishes that period from the preceding (Hu-t'o) 

 time. It was the absence of marine life and the character of the 

 sediments that led me to conclude that there were no marine depos- 

 its on the North American continent (nor probably on any of the 

 continents) representing the Lipalian interval or the interval be- 

 tween the fossiliferous Cambrian formations and the period of the 

 development of the early pre-Cambrian marine life along the shores 

 of the continents.^ 



I now anticipate that if the rocks of the Wu-t'ai and Hu-t'o sys- 

 tems are studied with the view that they may not be of marine' origin, 

 they will be found deposited as epicontinental sediment accumu- 

 lated on flood plains or in bodies of fresh water. In part they are 

 more altered and metamorphosed than the pre-Cambrian sedimen- 

 tary rocks of North America, and hence it may be more difficult to 

 determine their origin. 



^WiUis, Bailey. Research in China, Pub. No. 54. Carnegie Institution of 

 Washington, Vol. 2, 1907, Systematic geology, pp. 4-20. 



^ Pre-Cambrian fossiliferous formations, C. D. Walcott, Bull. G. S. A., 

 Vol. ID, p. 199, 1899. 



'Willis, Bailey. Research in China, Vol. 2, 1907, Systematic geology, p. 7- 



* Walcott, C. D. Smithsonian Misc. Coll., Vol. 57, Cambrian Geology and 

 Paleontology, No. i, 1910, Abrupt appearance of the Cambrian fauna on the 

 North American continent, pp. 14, 15. 



