Notes 337 



Notes. 



At a meeting of the Biological Society of Washington, on 

 February 7, Mr. Charles D. Walcott, of the U.S. Geological 

 Survey, announced the discovery of vertebrate life in the 

 Lower Silurian (Ordovician) strata. He stated that " the 

 remains were found in a sandstone resting on the pre- 

 Palseozoic rocks of the eastern front of the Eocky Mountains, 

 near Canon City, Colorado. They consist of an immense 

 number of separate plates of plaeoganoid fishes, and many 

 fragments of the calcified covering of the notochord of a 

 form provisionally referred to the Elasmobranchii. The 

 accompanying invertebrate fauna has the facies of the 

 Trenton fauna of New York and the Mississippi valley. It 

 extends into the superjacent limestone, and at a horizon 180 

 feet above the fish beds, seventeen out of thirty-three species 

 that have been distinguished are identical with species 

 occurring in the Trenton limestone of Wisconsin and New 

 York. Great interest centres about this discovery from the 

 fact that we now have some of the ancestors of the great 

 group of placoderm fishes which appear so suddenly at the 

 close of the Upper Silurian and the lower portion of the 

 Devonian groups. It also carries the vertebrate fauna far 

 back into the Silurian, and indicates that the differentiation 

 between the invertebrate and vertebrate types probably 

 occurred in Cambrian time." Mr. Walcott is preparing a 

 full description of the stratigraphic section, mode of occur- 

 rence and character of the invertebrate and vertebrate 

 faunas, for presentation at the meeting of the Geological 

 Society of America, in August next. 



At the annual general meeting of the Geological Society 

 of London, held on Feb. 20th last, the Bigsby medal was 

 awarded to Dr. G. M. Dawson of the Geological Survey of 

 Canada. This is a well deserved honour which Canadians 

 will fully appreciate. 



