New Species of Cladodus. — Hay. 373 
DESCRIPTION OF A NEW SPECIES OF CLADODUS 
(C. FORMOSUS) FROM THE DEVONIAN 
OF COLORADO. 
By O. P. Hay, New York. 
This species is based on a single specimen which was col- 
lected in the year 1900 by Mr. Whitman Cross of the U. S. 
Geological Survey. It was found in the Ouray limestone of 
the Needle Alountain quadrangle, at the northwest edge of 
Lime mesa, which is on the south slope of the Needle moun- 
tains, in western Colorado. Dr. George Girty, who has de- 
scribed the invertebrate- fossils of this formation, informs us 
(U. S. Geol. Surv. 20th Ann. Rept., pt. 11. 1900, p. 35.) that 
it belongs to either the late middle or early upper Devonian. 
The fossil is borne on a piece of limestone which was found 
loose on a ledge of the Ouray limestone ; but there are no 
higher formations at that part of the mesa, as I am informed 
by Mr. Cross ; hence its origin is unquestionable. 
As to the character of the fauna of this formation. Dr. Gir- 
ty informs me through Mr. Cross that it is a clearly defined 
Devonian fauna, containing no Lower Carboniferous forms. 
Fig. i. Cladodus Formosus. Hay, X2. 
The tooth is firmly imbedded in a hard limestone, the an- 
terior face being exposed ; and I have not ventured to remove 
it. Consequently, the character of the posterior face is un- 
known. The tooth (Figure i, X 2) is of median size. The 
hight of the principal cusp, measuring from the lower line 
of the base, is 10.5mm. The base from one extremity to the 
other ecjuals ismm. Seeti from the front the extremities of 
the base are narrow. In the midline the base is rather deeply 
sinuated; while between the sinus and the extremities the 
outline is convex. 
From the base spring the large median cusp and two 
pairs of small lateral cusps. The width of the principal cusp, 
