490 NEW YORK STATE MUSEUM 



cally, have discouraged investigators and collectors from study- 

 ing this unfruitful terrane. Thus, for example, the Hudson river 

 beds were left out of consideration by N. H. Darton in his invests 

 gation of the stratigraphy of the formations of Albany county 

 (48)1. 



The writer has tried to approach the problem by systematically 

 visiting and collecting at all outcrops in a rather limited terri- 

 tory, embracing the banks of the Hudson river and its tributaries 

 between Waterford, 8 miles north of Albany, and Coeymans, 13 

 miles south of Albany. This region contains many of the locali- 

 ties where fossils were found before, and among them also the 

 classic collecting grounds of the Normans kill (Kenwood) and the 

 Abbey (Glenmont). A number of new localities have been found, 

 which, by their arrangement in zones and by their fossil contents^ 

 allow a step forward toward the solution of the problem and 

 justify the present publication. 



HISTOEY OF THE HUDSON RIVER BEDS 



The history of the problem of the Hudson river beds has been 

 treated, though only in regard to the validity of the term, by 

 James Hall (17) and C. D. Walcott (36a), to whose papers the 

 reader may be referred here. 



W. W. Mather 



The term '^ Hudson river slate group " was proposed in 183& 

 by Mather, in his annual report on the geology of the first dis- 

 trict (1), where he says (p. 212): " (1) The lowest in the series [of 

 fossiliferous rocks] is the Htidson river slate group, consisting of 

 slates, shales and grits, with interstratified limestones, all of 

 which occur under various modifications. This group is overlaid 

 unconformably in many places by the various rock formations of 

 more recent origin." The following fossils (graptolites) are men- 

 tioned besides a few shells: "Fucoides serra, F. den- 

 tat u s , and two other species which are probably F. 1 i n e - 

 a t u s and F. r a m u 1 o s u s ". 



^See References, p. 581. 



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