]20 GEOLOGY. 



The author thus summarizes his conclusions regarding these Am- 

 monoosuc Helderberg beds: — 1. The fossiliferous limestones belong to 

 the Lower Helderberg. 2. The Helderberg series in New Hampshire 

 is several thousand feet thick, and is composed chiefly of limestones, slates, 

 sandstones, conglomerates, and probably hornblende rock. Some of 

 the members are highly metamorphic. 3. These Helderberg beds seem 

 tb be newer than the Coos group of the neighbourhood ; their litholo- 

 gical character is also difl'erent. 4. The Swift- Water series seems more 

 nearly related to the Helderberg than to any of the other formations. 

 5. The Helderberg rocks are the newest in this "terrane," and the 

 most modern that have yet been discovered in the State. G. A. L. 



HoLLEY, Geoege W. The proximate Euture of Niagara ; in Review 

 of Professor Tyndall's Lecture thereon. Proc. Amer. Assoc, 

 vol. xxii. B. pp. 147-155, with plan in text. 

 Contradicts several of the statements respecting the geological struc- 

 ture of the Palls in Prof. Tyndall's lecture. 



HoNEYMAK, Dr. D. Geology of the Cobequid Mountains, Nova Scotia. 



Amer. Journ. ser. 3, vol. vii. pp. 148, 149. 

 Abstract of paper in Proc. Nov. Scot. Inst. (1874?) 



— — -. On the Quaternary containing the New Brunswick fossil 

 cetacean ; on Niagara Coral reefs ; and on Niagara fossils in trap. 

 Amer. Journ. ser. 3, vol. viii. pp. 219, 220. 



Notes in a letter. 



Hfnt, Dr. T. S. The Coal and Iron of Southern Ohio considered with 

 relation to the Hocking-Yalley Coal Pield and its Iron ores, with 

 notices of Purnace coals and Iron-smelting, followed by a view of 

 the Coal Trade of the West. Pp. 78, two maps. 8vo. Salem, Mass. 

 The introduction consists of a general description of the principal 

 geological features of the Appalachian Coal-basin. Details as to the 

 strati graphical relations of the various workable seams in the Hocking- 

 Yalley Coal-fields are next given, with (further on) analyses of the 

 coals. The same is done with regard to the iron-ores of the region. 

 The rest of the report is of a commercial character. Both maps are 

 topographical only, with this exception, that the approximate limit of 

 the coal-bearing series is shown on the first. G. A. L. 



The Geognostical History of the Metals. Trans. Amer. Inst. 



Min. Eng. vol. i. pp. 331-346 (with discussion). 

 Divides the crystalline stratified rocks of Eastern North America into 

 four groups, lithologically and strati graphically distinct — Lauren tian, 

 Norian (or Labradorian= Upper Laurentian of Logan), Huronian, and 

 Montalban (gneiss and mica-schist of the White Mountains), — and 

 thinks it probable that other like formations of crystalline rocks may 

 liave been almost entirely swept away. The Laurentian is remarkable 

 for deposits of crystalline iron-ore, chiefly magnetic, the ores occurring 

 in beds or masses of contemporaneous deposition. The Norian is re- 



I 



