REPORT OF THE STATE PALEONTOLOGIST 1901 437 



literature as the Hudson river slates, Rudolf Ruedeinann, as- 

 sistant paleontologist, has extended the work previously done 

 and reported on, in the vicinity and to the south of Albany 

 (museum bulletin 42) northward into the upper reaches of the 

 Hudson valley and the general field of exposure of the forma- 

 tion in this direction. On the west side of the river the Lorraine 

 and Utica beds have been traced as far as Mechanicsville; on 

 the east side the Utica, middle Trenton and Normans kill shale 

 were followed only a few miles northward to the long outcrops 

 on the Deep kill in Rensselaer county. At this point a most 

 interesting discovery was made in the finding of beds contain- 

 ing a very unusual graptolite fauna in a fine state of preserva- 

 tion; such a fauna as was described at an early date by the late 

 Prof. Hall from the so called Quebec shales of Canada. Of this 

 fauna nothing has before been known in the state of New York, 

 and the presence of these fossils here in such abundance 

 affords not only important points of correlation of the New 

 York with the Canadian faunas, but again adds in a" notable and 

 interesting way to the ancient faunas of the state. Though this ^ 



fauna is embedded in the " Hudson river slates ", its age as 

 indicated by the character of its fossils is doubtless to be as- 

 cribed to that of the Beekmantown formation, and represents 

 in an unbroken succession the faunas of horizons which have 

 hitherto in America been known only separately and without 

 any clue to their chronologic sequence. From a biologic point 

 of view the interest of the discovery is greatly enhanced by the 

 presence of innumerable growth stages representing the entire 

 development phases of many forms, from the embryonic stage 

 to the fully developed colony. This interesting section occurs 

 near the town of Melrose in northwestern Rensselaer county, 

 and its graptolites are representatives of the genera Phyllo- 

 graptus, Tetragraptus, Loganograptus, Dichograptus, etc., 

 which have hitherto been foreign to our faunas. Four different 

 aggregations of graptolite-bearing shales were found in the 

 thick mass of thin bedded limestones and greenish grits which 

 ^compose the outcrop; and, as the aggregations or faunules are 



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