HUDSON RIVER BEDS NEAR ALBANY 499 



p. 34, Op. oit,), obviously on the ground (p. 2) " that the Utica 

 «late formation was traced by the New York geologists down the 

 Mohawk valley from Oneida county through Herkimer, Mont- 

 gomery, Schenectady and Saratoga counties to the shores of the 

 Hudson", and that ^^ Prof . W. W. Mather gives the following 

 localities in the Hudson river valley below Bakers falls, where 

 the Utica slate is to be observed with its characteristic grapto- 

 lities, at Wat erf or d, Ciohoe^, Normans kill below Albany, at Hud^ 

 «on," etc. The evidence which the graptoliteis at Normians kill 

 afforded to Whitfield of the equivalency of the graptolitic slates 

 «,nd the Utica slate, is also cited. 



As these citations prove, Walcott based his correlation on the 

 continuity of the shales of the Mohawk valley with those of the 

 Hudson valley and on the Utica slate localities in the Hudson 

 valley as mentioned by Mather, and finally on Whitfield's asser- 

 tion of the partial identity of the Normans kill and Utica faunas. 

 The first argument has been meanwhile weakened by the estab- 

 lishment of the presence of a fault between the disturbed and 

 undisturbed regions, which was already assumed by Emmons, 

 and will be spoken of farther on (p. 504). Mather's assertion 

 of the presence of a zone of Utica shale localities in the Hudson 

 valley was caused, as shown above, by his failure to distinguish 

 between the Normans kill and Utica shale graptolites ; and Whit- 

 field's correlation has just been discussed on the preceding pages. 



T. N. Dale 



In the same year T. Nelson Dale (20) discovered in an outcrop 

 of argillaceous schist about a mile west of the Hudson opposite 

 Poughkeepsie_, . crinoid stems, Orthis testudinaria, O. 

 pectinella, Leptaena sericea, Strophomena 

 alternata, Bythotrephis subnodosa and a cast of 

 a gastropod which resembles Bellerophon bilobatus 

 (all being Hall's identification), some of these fossils being also 

 iound near Vassar college and south of Poughkeepsie. 



The author concludes from his determinations that "the clay 

 filates and shales in the vicinity of Poughkeepsie, on both sides 

 of the river, are fossiliferous and that they very probably belong 



