Geology and Mineralogy. 149 



smaller bed prevented transmission of the heat and changes in the 

 coal. Actual contact with the molten rock appears necessary to 

 produce change, for the upper sheet of trachyte comes down to 

 within a few feet of the White Ash and evidently has no effect 

 upon its composition ; the transition from bituminous to anthra- 

 cite in that coal bed is regular from the north southward under 

 the sheet, and apparently in no greater ratio than in the Cook- 

 White, 150 feet lower, which in turn is fully 200 feet above the 

 lower sheet. 



6. Note on the Trap Hock of the Palisades ; by Bexj. Smith 

 Lyman (from a letter to the editors, dated Philadelphia, Jan. 7, 

 1896). — In the January number of this Journal (p. 4), Prof. Wm. 

 M. Davis refers to my recent report on the New Red of Bucks 

 and Montgomery counties, in the Pennsylvania Geol. Surv., final 

 report, vol. iii, p. 2621, for a brief argument of mine against the 

 intrusive character of the trap of the Palisades. It may be 

 worth while, for the benefit of those interested in the subject, to 

 call attention also to a little fuller discussion of the point in the 

 Proceedings of the American Philosophical Society, vol. xxxiii 

 (1894), p. 195. The intrusive character seems to him "undoubt- 

 able." To others it seems not only doubtable, but entirely con- 

 trary to observed facts. He speaks of the great length (over 

 fifty miles) of the Palisades trap as the only argument against 

 him ; and, indeed, it seems to be of itself an invincible one when 

 taken in connection with the other circumstances, such as the 

 soft shaliness of the sedimentary beds, their gentle dip, the great 

 crookedness of the outcrop, and the exact conformity of the trap 

 beds (not a single bed) to the shales, as made thoroughly evident 

 by the topography of the whole region — not merely " rough" 

 conformity, as he conjectures without substantial proof. 



It used to be imagined that volcanic rock, or trap, forced its 

 own way, as a solid wedge might, through hitherto unbroken 

 rock beds, separating them and even lifting them up, to open a 

 passage. It is sufficiently incredible that such a passage would 

 adhere to one bedding plane around basins and saddles in soft, 

 gently dipping shales for a distance of fifty miles. But, taking 

 the view that igneous rock in general merely flows into crevices 

 it finds open, it becomes still more inconceivable that they could 

 have opened along a single bedding plane in such shales, with 

 such dips and such an irregular structure, for such a distance. 



7. Missouri Geological Survey. — The Annual Report for 1894, 

 received November, 1895, contains the 3d biennial Report of the 

 Director, pp. 1-79; the subjects discussed are: The Crystalline 

 Rocks of Missouri, Erasmus Hawortit, pp. 81-224 — map, and 

 plates xii-xxx, chiefly micro-photo lithographs; Dictionary of 

 Altitudes, by C. F. Marbut, pp. 225-316; Characteristics of Ozark 

 Mountains, by Chas. R. Keyes, pp. 317-352, and Coal Measures 

 of Missouri, by Garland C. Broadhead, pp. 353-395. 



8. Iowa Geological Survey. — The third Annual Report, 1894, 

 under the present state geologist, Samuel Calvix (pp. 1-467, 



