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NEW YORK STATE MUSEUM 



of the little house north of Mr R. J. Kimlin's barn. The ledge 

 carrying Solenopora com pacta found by Professor Dwight 

 is only a short distance to the southeast. 



In the summer of 1908 a new Potsdam locality was discovered 

 by the writer. The beds yielding fossils were found in the quarry 

 on the Ruppert farm about 200 yards north of the Spackenkill road. 

 The rock was being removed for lime and blasting operations greatly 

 facilitated the search for fossils. These are scattered and usually 

 fragmentary. They are embedded in compact, resistant limestone 

 which made the search difficult. A half dozen good specimens of 

 L i n g u 1 e p i s p i n n i f o r m i s were found, besides numerous 

 fragments ; also a head of P t y c h op a r i a sp. A photograph of 

 the quarry is shown in plate 7. Fossils seemed most abundant in 

 the middle layers. Figure 16 shows two of the best preserved speci- 

 mens of L. p i n n i f o r m i s . 



Fig. 16 Two specimens of Lingulepis pinniformis from the arenaceous Upper Cambric 

 limestone beds at Ruppert's quarry 



The rock in the floor of this quarry showed many peculiar mark- 

 ings of concentric rings from three-fourths to one inch in diameter. 

 These were sectioned and examined by Professor John M. Clarke. 

 A part of a letter from Dr Clarke referring to these structures is 

 given below. 



^' I have had the specimen you sent to me cut and polished in the 

 hope of bringing out some structure from the concentric masses 

 therein. The result is not very satisfactory, except as indicating 

 what seems to be an inorganic origin, though I would not be willing 

 to say that the masses were not spongoid like Streptochaetus. The 

 successive laminae might indicate such a structure, but the intimate 

 composition of the skeleton has been so altered by granulation as 

 to seem to leave possibility of organic structure pretty hazy; yet I 

 am inclined to believe that the rock carries organic remains, as 



