Haworth en the Archc£an Geology of Missouri. 281 
(c) Sti-ucture of the porphyries. (</) Classification of the por- 
phj'ries. 
C. Diabase and Diabase Porfhyrytcs including all the dyke rocks, 
(a) Mineralogical composition. (U) Special description of^minerals. 
(c) Structure of the diabases. ((/) Classification of the diabases. 
D. General Conclusions. 
LITERATURE. 
Broadhead, G. C. : Notes on such rocks of Missouri as admit of a high 
polish. Mo. Geol. Rep., 1872, p. 414. 
Geology of Madison county. Mo. Geol. Rep., 1S73-74 
Geological notes of S. E. Missouri. Published in Mines, Metals 
and Arts, St. Louis, June, 1876. 
S. E. Missouri lead district. Eng. and Mining Journ., June, 1876. 
^Age of our porphyries. Trans. St. Louis Acad. Sci., vol. 3, pp. 
366-370, 1S77. 
Marbles of S. E. Missouri, Kan. City Review, vol. 5, p. 323, 1S82. 
Archaean rocks of Missouri, " " " vol. 5, p. 733, 1882. 
Frazer, Persifor: On some geological features of Iron Mountain and 
Mine La Motte, Missouri. Phil. Acad. Sci. Proc, vol. 26, pp. 85-86. 
Gage, James R.: On the occurrence of iron ores in Missouri. Trans. 
St. Louis Acad. Sci., vol. 3, pp. 181-192. 
Harrison, Edwin: Age of Porphyry Hill, S. E. Missouri. Trans. St. 
Louis Acad. Sci., vol. 2, p. 504. 
Litton, A.: Geology of Iron Mountain, Pilot Knob and vicinity. Mo. 
Geol. Rep. 1855. Part II, p. 75. 
Newton, Henry,: Iron ores of Missouri. Trans. Am • Inst. Min. Eng., 
vol. 3, p. 377 and 389. 
Pumpelly, Raphael,: Notes on the geology of Pilot Knob and vicinity. 
Mo. Geol. Rep., 1872. 
Schmidt, Adolf.: Iron ores of Missouri. Mo. Geol. Rep., 1S72. 
Schoolcraft, H. R.: View of the lead mines of Missouri. New York, 
1819. 
Shumard, B. F.: Geology of Ste. Genevieve county. Mo. Geol. Rep., 
1855 to 187 1. 
Swallow, G. C: Metamorphic and igneous rocks of Missouri. Mo. 
Geol. Rep., 1855. Part I. 
Whitney, J. D.: Metallic wealth of the United States. Philadelphia, 
1854, pp. 479-480. 
A few other notices and short articles have been published in different 
journals, references to which I could not obtain. 
