THE NEW YORK STATE SURVEY. 337 



a few fucoids and graptolites and a few specimens of testacea, none of which 

 were designated by name. 



Mr. Larduer Vanuxem accepted the term proposed by Dr. Mather, and 

 described the Hudson River group as he found it in the Mohawk valley. 

 It there rests upon the Utica slate throughout the district, and is next in 

 order as to age. It is followed by the gray sandstone of Oswego, the rock 

 which immediately succeeds it in the district where that rock exists.* 



He further says : 



The name is adopted as being generally used in the Survey and as being more com- 

 prehensive than the one heretofore used ; it is, however, objectionable from the diffi- 

 culty in defining its limits along the region of the Hudson river. 



In Schoharie county the Hudson group is undisturbed and unaltered, and its maxi- 

 mum thickness is not less than 700 feet, but from the absence of the succeeding rock 

 its precise position is not made known. Further west, in the same district, the' whole 

 series is complete and its position well denned. f 



Mr. Vanuxem considered this group one of the universal ones, and that 

 its two divisions are not coextensive : the lower one enters the first dis- 

 trict along the Mohawk, and extends north by Rome through Lewis into 

 Jefferson county ; the upper division first appears in Oneida county, and 

 from thence west and north it is an associate of the Frankfort slate or the 

 lower division. 



The sandstone-shales of Pulaski are fossiliferous portions of the second or 

 upper division of the Hudson River group. As respects its fossil history, it 

 will probably be subdivided, from the following facts: Fossils are rare in 

 the lower part of the Frankfort slate, but are numerous where it joins the 

 next series, the Pulaski shales. There is no essential difference between the 

 fossils of this place, whether seen at the mill-race at Lee Centre or Whitall's 

 quarry near Rome, at Halleck's spring iu Hampton or in the gully near Utica 

 or on the Cohoes near Waterford. In all these localities the group of shells 

 which so peculiarly characterize the Pulaski shales is wanting, and others 

 appear that had no previous existence in the district. J The upper division, 

 or Pulaski shales, is stated to be characterized by Cyrtolite* ornahis, Am- 

 bonychia radiata, Modiolopsis modiolaris M. eurva, M. ovata; also Orlhon<<f't 

 parallella, and other species not yet described. 



Rome, New York, is given as the first locality west of the Hudson where 

 the upper division is found. To the west of Rome, and north through 

 Lewis county, it covers a large portion of the west side of the range of the 

 Hudson River group. In Ohio and Indiana the upper division is seen with 

 its fossils; the lower one has not yet been observed. It is there highly 



*Geol. N. Y., Survey Third Geol. Disfc, 1842, pp. 60-C7. 

 fLoc. cit., pp. 60-61. 

 I Loc. cit., p. 64. 



