JURASSIC ROOKS OF M°KENZIE RIVER. 



307 



northern locality, not only for the purpose of determining 

 the age of the formation, but for the light they might 

 throw upon far more interesting questions respecting the 

 probable climatic conditions in these high northern lati- 

 tudes during the secondary period.] 



After the above paragraph was published in my report 

 on the expedition, page 182, Mr. Meek has written to me 

 to say : " Since writing the paper on these fossils for your 

 report, I have seen some figures of Jurassic species from 

 the Aleutian Islands as high north as* about the 58th 

 parallel. Amongst these there is' an Ammonite (A. Was- 

 nesseuski, Grewingk. — Trans. Mineralogical Society of 

 St. Petersburg!!, 1848-9, PL IV.) resembling one of those 

 I have described in your report (A Barnstoni) so nearly 

 in some of its characters, as to strengthen my suspicions 

 that the rock from which these fossils were obtained on 

 McKenzie's Eiver may prove to be of Jurassic age. In 

 the peculiar deep conical characters of the umbilicus of 

 A. Wosnessenski, it is very similar to A. Barnstoni but it 

 is a more compressed shell, with straighter and more 

 simple costae ; while its septa, if accurately drawn differ 

 from those of A. Barnstoni, I am rather inclined to the 

 opinion that these rocks on McKenzie's Eiver will prove 

 Jurassic, but we must wait for additional evidence before 

 any positive opinion can be given." 



The Eev. Samuel Haughton, F.E.S., discusses the ques- 

 tion of climate in the Arctic regions in relation to the 

 Liassic fossils found in situ on Prince Patrick Island and 

 elsewhere north of the 75th parallel, in the geological 

 account of the Arctic Archipelago, published in the Appen- 

 dix to Captain McClintock's Narrative. Professor Haugh- 

 ton says, " But what are we to say as to the question of 

 temperature ? It was certainly necessary for an Am- 

 monite to have a sea free from ice, on which to float and 



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