Geology and Natural History. 85 



formation from Vermont to Tennessee." "The superjacent lime- 

 stones carry the Olenelhis fauna in their lower portions in northern 

 and southern Vermont, eastern New York, New Jersey and 

 Pennsylvania. To the south of Pennsylvania the lower portions 

 of the limestones appear to be represented by shales, and the 

 Upper and Middle Cambrian faunas are found in the lower half 

 of the Knox dolomite series of Tennessee, and they will probably 

 be discovered in the same series in Virginia and Maryland when 

 a thorough search is made for them. The same may be predicted, 

 but with less assurance, for the northern belt of limestone cross- 

 ing Pennsylvania into New Jersey, as the limestones between the 

 Olenellus zone and the Trenton zone represent the intervals of 

 the Middle and Upper Cambrian and the lower Ordovician, or 

 the Calciferous and Chazy zones of the New York section. The 

 working out of the details of this section in southeastern Penn- 

 sylvania is an interesting problem left for solution to some geolo- 

 gist who has the necessary paleontologic training, and who will 

 not be discouraged by the prospect of a good deal of hard work 

 before the desired result can be obtained." 



" The problem of where to draw the line in this series of lime- 

 stones, on a geologic map, between the Cambrian and Ordovician, 

 is one that will seriously embarrass the geologist, but I anticipate 

 that either lithologic or paleontologic characters will be dis- 

 covered by which the two groups can be differentiated." 



The final seven j^ages and six plates are devoted to the con- 

 sideration of intratormational conglomerates, — that is, of con- 

 glomerates "formed within a geologic formation of material 

 derived from and deposited within that formation." ' In explaining 

 their origin, Mr. Walcott believes that the sea bed was raised in 

 ridges or domes above sea level, and thus subjected to the action 

 of shore ice, if present, and the serial agents of erosion. 



The following are the Folios which have been recently issued : 

 No. 21. Pikesville, Tenn., lat. 85°-85° 30', long. 35° 30-86°, by 



W. C. Hayes. 

 No. 22. McMinnville, Tenn., lat. 85° 30-86°, long. 35° 30-36°, by 



W. C. Hayes. 

 No. 23. Nomini, Md. & Va., lat. V6° 30'-V'7' 



by N. H. Darton. 

 No. 24. Three Forks, Mont., lat. lil°-112° 



A. C. Peale. 

 No. 25. Loudon, Tenn., lat. 84°-84° 30', long. 



Arthur Keith. 



Crater Lake, (Oreg.), Special Topographic Sheet with illustra- 

 tions and geologic text on back, by J. S. Diller. 



2. American Paleontology Prize. — A prize of fifty dollars is 

 offered by Prof. G. D. Harris, editor of the Bulletins of Ameri- 

 can Paleontology, for " the best American (North, Central or 

 South) paleontological article presented for publication, as a sepa- 

 rate bulletin, before May 1, 1897. The article must be a well 



long. 



38°- 



-38° 



30', 



long. 



45° 



-46°, 



by 



^ 35^ 



30' 



-36°, 



by 



