212 FOREST LANDS OF NORTHERN RUSSIA. 



nated among vegetables, but only within the perimetre ot 

 a littoral zone of rather limited extent.' 



The productus and spirifer spoken of are bivalves like 

 the cockle and mussel, the shells of which are found 

 with many others in the mountain limestone, and in it 

 alone. What is so called is, as has been stated, a series of 

 limestone strata lying immediately below the coal measures, 

 and, in some cases, alternating with them. They extend 

 over great part of Central and Northern Europe; they 

 are found again in the lake district of America, and they 

 extend to the borders at least of the Arctic Ocean, extend- 

 ing between the parallels of 60 and 70, stretching 

 towards the mouth of the Mackenzie River. The nature of 

 the organic remains found in them, as well as the con- 

 tinuity of the calcareous beds of homogeneous mineral 

 composition and the great thickness of the deposits, concur 

 to prove that the whole series was formed in a deep and 

 extensive ocean, in the midst of which, however, there 

 were many islands. Amongst other characteristic fossils 

 are the encrinites, popularly known in some localities as 

 St. Cuthbert's beads and ammonites, and the bivalves 

 mentioned. 



After tracing the relations of numerous allied plants, 

 and the characteristics of those found in different localties, 

 and the successive changes observable in strata of succes- 

 sive formation, he states that the primaeval type, or palse- 

 zoic stock, of the Salisburias and their allies appears to be 

 the Psygmophyllum of Schemper, and that in all the cir- 

 cumstances of the case it might have been expected that 

 some remains of plants possessing the same characteristics 

 would be found in Bear Island. Such he considered 

 remains figured by M. Heer under' the name of Cardiop- 

 teris polymorpha et frondosa* 



Count Saporta then gives some details in regard to the 



* Kohlen ft. d. B"<ren. Tnscl. ; tab. xiv., fi. 1-4. 



