172 The American Geologist. March, 1905 
"tains present so extraordinary a structure as in New Spain. 
«* * • • Those immense plains elevated to the hight of our 
"highest mountains; those gigantic peaks hewn with such regularity 
"into conical forms; those abrupt chasms, so deep that the eye can 
"scarcely penetrate their gloomy abyses; — nothing in our regular 
"formations has prepared us to see and comprehend these things, 
"nothing fills the space which exists in our minds between our pre- 
"vious observations and that which suddenly strikes our view." 
Very remarkable, too, are the horizontal beds of chalk-like de- 
posits called "Sillares" overlying the water-bearing stratum of 
gravel, the more so as they, in common with the hard limestone 
appear to be absolutely non-fosiliferous. 
Finding that my friend, Mr. Ernest Wittmann, a scientific 
Austrian gentleman residing at Monterey had spent considerable 
time in studying these interesting features, I suggested that he 
write out some of the results of his investigations, particularly as 
so little seems to be known of the geologj- of this part of Mexico. 
He has complied with my suggestion, and hopes, with me, that th^ 
inclosed manuscript may prove of suflBcient merit to justify its 
publication in your columns. 
220 West 57tb St., E. Sherman Gould. 
Xew York. 
The city of Monterey in the state of Xuevo Leon, well 
known as one of the best developed centers of industry of 
the republic of Mexico, is also a ver\' interesting point for 
geological study. 
On the southerly side of the city, rises the great range 
of the eastern Sierra Madre with its picturesque foot hills ; 
east of it. and divided from it by the deep and narrow 
Huajuco canyon, the Sierra de la Silla, or Saddle mountain, 
rears its lofty peak. 
West of the city are the foot hills of a mountain range 
called the Sierra de la Mitra, a branch of the Sierra Madre. 
Upon these foot hills stand the ruins of the old "Bishop's 
Palace.'' partly destroyed by the cannon balls of general 
Taylor. 
Between the Sierra Madre and the Sierra de la Mitra. 
lies the valley of Santa Catavina through which runs the 
river of the same name. On the north side of the cit\ 
stretches a level plain, some portions of which are verv* fer- 
tile and yield rich harvests of corn, sugar cane and vegeta- 
bles. 
About five miles north of the city this plain is broken 
