GEOLOGY AND PALEONTOLOGY. 185 
FAUNA OF THE PERMIAN OF THE CENTRAL UNITED STATES. 
PART I. 
BY J. W. BEEDE. 
Read before the Academy December 29, 1901. 
It is proposed to give under the above title a discussion of the stratigraphy, 
fauna and faunal relationships of the Permian of the Mississippi valley. An ar- 
ticle is now in preparation on the fauna and stratigraphy of a portion of the 
Lower Permian (below the Red Beds). A preliminary note on the fauna of the 
Upper Permian (Red Beds) may be found in the forthcoming report of the Okla- 
homa Geological Survey. 
The object of this paper is merely to bring to notice a few very interesting 
species not heretofore known, leaving most of the discussion of them to the later 
paper, where the fauna will be discussed more fully and the descriptions and 
figures of the fauna as a whole given. 
NEW SPECIES FROM NEBRASKA, 
The fossils herein described are from a valuable collection made in Gage 
county, Nebraska, by Prof. W. C. Knight. The discussion of the geology of this 
region will be found on page 307 of the eighth volume of the Journal of Geology.* 
The specimens herein described are now in the museum of the University of Ne- 
braska. 
Aviculopecten nebrascensis, n. sp. Plate XIII, figs. 3-3d. 
Shell moderately large, quite convex, somewhat resembling A. occidentalis 
Shum. in general appearance. The posterior ear of the left valve is moderately 
small, the posterior margin being only slightly sinuated below it. The anterior 
ear is moderately well rounded in front, with deep sinus below; sulcus between 
the ear and body of the shell not very well defined. Hinge line about two-thirds 
the length of the shell; beak widens rapidly, slightly protruding. Except near 
the ears, the shell is moderately regularly rounded. The surface is marked by 
radiating striz or costz, sometimes wavy, and occasionally one is larger than the 
majority, increasing by implantation. The right valve is flat, with the byssal 
notch extending to the body of the valve; the markings of the body of the valve 
similar to those of the other half of the shell. Length, 33 mm.; height, 31 mm.; 
convexity, 10 mm.; length of hinge, 21 mm. 
Permian, Gage county, Nebraska. 
This species seems to be derived from A. occidentalis, and differs from it in 
the small posterior ear, great convexity, and the wide-angled beak. 
Pinna? coprolitiformis, n. sp. Plate XIII, figs. 1, 10. 
Shell moderately small for the genus; angle of divergence large; hinge nearly 
straight; ventral margin apparently irregular; anterior end blunt. The entire 
shell is wrinkled vertically and has little the appearance of the usually graceful 
species of the genus. The markings and lines of growth are very indistinct in 
our specimens. These markings are very much like those of Aviculopinna, but 
are very faint and very fine. Length, 50mm.; height in widest portion, 30 mm.; 
convexity, about 22 mm. 
Permian, Gage county, Nebraska. 
The generic position of this fossil is uncertain, as the beak is not well pre- 
served. It seems to have more nearly the general form of a Pinna than of an 
*See, also, an article on the Blue Valley Permian, by the writer, in the Kansas University 
Quarterly for July, 1900, vol. IX, p. 191. 
