PEEFACE 



The prepai'ation of this memoir is the outcome of stratigraphic investiga- 

 tions carried on for several years in the slate belt of eastei-n New York. The 

 discovery of graptolite zones affording rich and well preserved faunas new 

 to the New York series of geologic formations, has made us acquainted 

 with graptolite facies of the important formations represented in the time 

 interval from the Upper Cambric to the end of the Lower Siluric. The 

 important bearing which the distribution, correct correlation and identifica- 

 tion of these graptolite faunas have on the geologic history of New York 

 in earlier Paleozoic time, and on Paleozoic paleography in general, demands 

 their monographic treatment, with special reference to range and geographic 

 distribution. 



On account of the very large amount of material to he considered, 

 it has been deemed advisable to divide this treatise in two parts, of 

 which this is the first. It contains the descriptions of the graptolites 

 of the Upper Cambric and Lower Champlainic (Lower Ordovicic), leaving 

 to the second part those of the Middle and Upper Champlainic (Trenton- 

 Lorraine) and of the Ontaric, or Siluric. 



In view of the facts that, since the publication of Hall's classical memoir 

 on the Quebec graptolites, 40 years ago, for the Canadian Greological Survey 

 (partly republished in the 20th annual report of the New York State Cabinet 

 of Natural History), no statement of the general results of graptolite researches 

 has appeared in print on this continent, and that the recent literature on this 

 subject is widely scattered, and some of ib difficult of access, this memoir is 

 introduced by a resume of the present status of our knowledge of graptolites. 



During the prosecution of this study, I have had the constant aid and 

 encouragement of the state paleontologist, to whom I am indebted for access 

 to literature connected with the subject and other necessaries of investigation. 



