158 The American Naturalist. [February, 
General Notes. a 
GEOLOGY AND PALEONTOLOGY. 
The Geological Structure of the Mount Washington Mass 
of the Taconic Range.-—The recent studies of Mr. Wm. H. Hobbs 
have disclosed new facts with regard to the Mount Washington Mass 
and the conclusions that the author draws from the data now known 
differ somewhat from those reached by Mr. Dana regarding the struc- 
ture of Mt. Washington. ; 
Mr. Hobbs’ paper is prefaced by the following brief account of the 
topography of the region in question: 
“That portion of the Taconic Range which is known as Mount Wash- 
ington is both topographically and geologically a unit. It covers an 
elongated elliptical area, about fifteen miles in length and four and 
one-half miles average breadth, lying in the states of Massachusetts. 
Connecticut and New York. It occupies the entire township of Mt. 
Washington and portions of Sheffield and Egremont in Massachusetts; 
about one-third of Salisbury in Connecticut; and portions of North- 
east Ancram, Copake and Hillsdale in New York. 
The Mt. Washington mass is a double ridge enclosing a summit 
plain. Mt. Everett, or the “ Dome of the Taconics ” (2624 ft.), lying 
in the eastern ridge, is the highest peak and one of the highest eleva 
tions in Massachusetts, while the Bear Mountain (2355 ft.) is the high- 
est point of land in the state of Connecticut. The main summit plain 
is situated to the northward centre of the mass and has an average 
altitude of about 1700 feet. Corresponding with the elliptical outline 
of the mountain, this plain is compressed at the north and south, 80 
that its length is about three miles and its breadth two miles. Eser 
cling it is a line of peaks ranging from 1900 to 2600 feet in height- 
This encircling wall of peaks is buttressed by other peaks both to the 
northward and to the southward, the southern side being strength ay 
by a parallel belt across the mountain, composed of Mts. Bear, Gri 
ley, Frissell and Monument. Southward of this belt of hills the ele 
vated plateau recurs, but without the rampart of peaks which char- 
acterize it in the northern and more central area. ille 
“The Salisbury-Sheffield valley on the east and the Copake-H 
dale valley on the west of the mass, constitute a floor having an a 
age altitude of 700 feet, from which Mt. Washington rises abrupt!) 
