274 IRVING. 



Trachytoid Phonolite. 



" IX. Large sheet in Squaw Creek. Specimens taken from 

 the dike-hke portion forming the " Gateway." Analysis by Pro- 

 fessor FHntermann, of Deadwood, South Dakota. 



X. Very coarse trachytoid phonohte from " Raum's Drill^'^ 

 in the bed of Calamity Gulch. Analysis by J. D. Irving. 



XI. Rock from the Mato Tepee or Devil's Tower. L. V, 

 Pirrson, American Journal of Science, Vol. XL, VII, p. 344. 



XII. Rock from Annie Creek, cut on the Burlington and 

 Missouri River Railroad. Analysis by Professor Flintermann, 

 of Deadwood, South Dakota. 



XIII. Rock from lower cut on the Burlington and Missouri 

 River Railroad, near mouth of Annie Creek. Analysis by Pro- 

 fessor Flintermann, of Deadwood, South Dakota. 



X/l\ Rock from irregular mass in the limestone to the 

 South of Calamity Gulch, and west of Elk Mountain. Analy- 

 sis by Professor Flintermann, of Deadwood, South Dakota. 



XV. Rock from thick sheet in the mouth of Annie Creek. 

 This rock has the typical texture of a tinguaite, and contains 

 some nepheline with much nosean and sanidine. There is also- 

 in very great abundance of the isotropic mineral at first supposed 

 to be leucite. Analysis by Professor Flintermann, of Dead- 

 wood, South Dakota. 



XVI. Rock from the summit of Green Mountain. - This is 

 a phonolite o trachytoid character, but possesses the typical 

 tinguaitic groundmass. In addition to this there is present 

 much of the same isotropic mineral referred to above. 



XVII Loose fragments from Annie Creek. Determined 

 as leucitophyre by Mr. D. H. Newland. Analysis by Profes- 

 sor Flintermann, of Deadwood, South Dakota. 



XVIII} Phonolite dike from Whitetail crossing in White- 

 tail Gulch. Analysis by Professor Flintermann, of Deadwood, 

 South Dakota. 



XI X.^ Rock from sheet in Whitetail Gu ch below Sugar 

 Loaf Hill. Analysis by Professor Flintermann, of Deadwood,. 

 South Dakota. 



