98 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 64 



The practically entire absence of the types of the Cambrian fauna 

 from all Alg-onkian rocks not only on the North American continent 

 but all continents is so sig"nificant that it is to me very strong 

 evidence that there was no sustained connection between the great 

 oceans swarming with a highly developed invertebrate life and the 

 epicontinental bodies of water in which the Algonkian limestones 

 and shales were deposited. 



The fauna of the Lower ? Huronian of Steeprock Lake, western 

 Ontario, was presumably derived from a marine fauna and possibly 

 lived under brackish-water conditions. The principal species of the 

 Steeprock Lake pre-Cambrian fauna, Atikokania lazvsoni,'' is prob- 

 ably a spongoid of a rather advanced stage of development, although 

 it suggests the Archaeocyathinse. We are here given a glimpse of a 

 fauna that existed near the base of the (Algonkian) ProterozL.j 

 and which must have had its beginnings in Archeozoic time. It 

 further indicates the presence of a sufficient supply of calcareous 

 matter in this inland water to form its skeleton and also a massive 

 limestone deposit in which its remains now occur. This also implies 

 calcareous beds in the great unknown Lipalian deposits of marine 

 waters on the borders of the continents. 



The recognized animal life includes several species of annelids 

 and one large species of crustacean that occur in the Greyson shales 

 just above the Newland limestone. This fauna is illustrated in 

 plates 21 and 22 of this paper. It was described along with doubt- 

 ful forms from the Grand Canyon series in 1899.'' 



Algal deposits. — The presence of an abundant algal flora is proven 

 by thick layers formed of the remains of Collenia {Cryptozoan^ in 

 former reports) in the Grand Canyon section where representatives 

 of the genus occur in limestones separated by 1500 feet (460 m.) 

 of intervening strata. In the Camp Creek section of Montana 

 Collenia was found to range up through 2,500 feet (760 m.) of 

 strata." 



In the Blackfoot series the vertical range is over 2,800 feet (850 

 m.). In 4 of the section fine specimens of Collenia two feet (0.6 m.) 

 and more in diameter occur in beds 3 feet (im.) thick." These 

 and beds near the Lewis and Clark Pass are reefs formed by 

 calcareous algae. 



Appendix to Memoir No. 28, Geol. Survey, Canada, 1912, p. 4. 



Bull. Geol. Soc. America, Vol. 10, 1899, pp. 232-239. 



I do not know a true Cryptozoon older than the Cambrian fauna. 



Bull. Geol. Soc. America, Vol. 17, 1906, pp. 4-5. 



Idem, p. 6. 



