wai.cott.I ADIRONDACK SUB-PROVINCE. 201 



Orthoceras, a gasteropod, and a forin resembling a cross-section of a 

 coral of the genus Zaphrentis. 



In a description of the southeast Missouri lead district Prof. Broad- 

 head gives a resum6 of the geology, and suggests that if the Lingula 

 (Lingulella) lamborni and Scolithus should be found in the Calciferous 

 group he would prefer to assign all the rocks from the lower sandstone 

 to No. 1, inclusive, as Calciferous. 1 The marble of southeastern Mis- 

 souri was referred in 1882 by Prof. Broadhead to the older series or 

 Potsdam, and the upper series to the Upper Silurian, with the state- 

 ment that Potsdam quarries are found in Madison, Iron, and Reynolds 

 counties. The marble beds will be spoken of in the summary of the 

 Cambrian rocks of Missouri. 2 



In a paper upon "The Geological History of the Ozark Uplift" Prof. 

 G. C. Broadhead describes, in 1889, 3 in a general way rocks referred to 

 the Potsdam and the Calciferous formations. Of these he says : 



The evidence is that the sandstones and magnesian limestones (Potsdam and Cal- 

 ciferous) were deposited in Arckean valleys of erosion, for they generally repose 

 nearly horizontally, or with slight inclination, upon the Archeau. 4 



EASTERN BORDER OR ADIRONDACK SUBrROVINCE. 



This includes the area about the Adirondack Mountains of New 

 York and the adjoining portions of Canada to the north. 



In a report of the geological structure of the county of Saratoga, 



Mr. J. H. Steele states that a conglomerated mass of rock is found in 



the town of Greenfield not far from its south line, on the southeast side 



of the Kayadarosseras Mountains, resting upon the primitive rocks. 



He says : 



It consists of rounded pebbles of quartz, from the size of a small shot to that of a 

 man's head, united into one common mass by a kind of coarse ferruginous sand. It 

 extends along the mountains to uo great distance, but fragments of it lay scattered 

 in all directions, and, indeed, are found aloug the whole extent of the south line of 

 the town of Greenfield, and in various other places. 6 



Under the heading of " Coarse Siliceous sandstone" a description is 

 given of an extended horizontal stratum along the west part of the 

 north line of the town of Saratoga Springs, and some way into the town 

 of Greenfield : 



It is a coarse, hard rock, resembliug common quartz in its fracture, but it is more 

 loose and granular in its structure. It is of a white color, and when heated and 

 thrown into water, crumbles into a line white sand. * * * I have been somewhat 

 at a loss to know where to place this formation, but from several circumstances I am 

 confident it should be placed among the oldest of the transition class. 6 



'The Southeastern Missouri lead district. Am. Inst. Mining, Eng., Trans., vol. 5, 1877, p. 102. 



2 M arble of southeast Missouri. Kansas City Review, vol. 5, 1882, pp. 524-526. 



3 Am. Geologist, vol. 3, 1889, pp. 6-13. 



4 Op. cit., p. 8. 



6 A report of the geological structure of the county of Saratoga. Memoirs of the Board of Agricul- 

 ture of the State of Now York, vol. 2, 1823, p. 53. 

 •Op. cit., p. 54. 



