No. 8.] SPENCER — GRAPTOLITES. 457 



GRAPTOLITES OF THE NIAGARA FORMATION. 

 By J. W. Spencer, B.A.. B.A.Sc, PhD., F.G.S. 



For many years, forms of life, allied or belonging to the 

 Graptolite family, have been known to occur in several places 

 throughout portions of the Niagara formation of New York. In 

 the second volume of the Palaeontology of New York, Prof. Hall 

 has described three species, and lately one has been described 

 by Professors Hall and Whitfield in the Palaeontology of Ohio, 

 all of which have been also obtained at Hamilton. The ancient 

 seas of Hamilton, Ontario, appear to have been very favourable 

 to their growth, as they have been found more abundantly here 

 than elsewhere. Among the large number of specimens obtained 

 nearly twenty species occur. Of these the writer has recognized 

 four mentioned below, and has ventured on the description of 

 thiee new genera and nine new species, hoping to complete the 

 work with descriptive plates at an early date. 



Whilst the Graptolites of other formations generally occur in 

 shales, those at Hamilton more frequently are found in the lime- 

 stones. Yet those obtained in the shales have their structure 

 better preserved. In most cases the poly paries are obscured, but 

 some of the specimens show their cells on one side. The corneous 

 structure is often well preserved, as also the corrugations and 

 depressions on the stipe. Different forms appear to be charac- 

 teristic of different beds of rock. As the various species show 

 great varietal differences, much difficulty arises in the way of the 

 student, and many fragments that appear at first sight to be 

 unlike, are found on close examination to belong to others whose 

 characters are recognized, or are too irregular in their forms to 

 establish specific relations. 



For six years I have been making a collection of Graptolites 

 whilst geologizing with my friend Lieut. -Col. Grant, H. P. 16th 

 llegt. But it is principally owing to the indefatigable researches 

 of that gentleman that so many Graptolites have been obtained, 

 and many that are in my collection of over 200 specimens were 

 collected by him. The earlier collections made by Col. Grant 

 were sent to the Geological Survey of Canada, and later to Prin- 

 cipal Dawson., LL.D., F.R.S., of iMcGiil University. To both 

 of these collections access was afforded. The types are at present 

 at the Canadian Geological Survey Office. 



