586 TRANS. OF THE ACAD. OF SCIENCE. 
- G. G. Shumard in Grayson 
County. The greatest thickness observed is in the vicinity 
of Austin, where the beds are exposed to the height of about 
one hundred feet. 
rganic Remains.—The most characteristic are Jnocera- 
mus biformis, Gryphea vesicularis, Exogyra costata, Ostrea 
anomicformis, Arca vulgaris, Radiolites Austinensis, ‘au. 
tilus Dekayi(?), Baculites auceps, Helicoceras, Ammonites, 
Cassidulus equoreus, Hemiaster parastatus, and scales an 
teeth of fishes. ; 
At the base we have shaly layers of dark bluish-gray, cal- 
careous sandstone, containing numerous fish-scales, teeth of 
orax heterodon, Lamna Texana, and remains of Mosa- 
urus. 
This assemblage of fossils establishes pretty clearly that 
the Austin Limestone represents divisions A, B and ©, of the 
Exoeyra arretrva Mart.—This is an indurated blue - 
yellow marl, with occasional bands of gray limestone, is 
ita, 
. ‘ ra 
Fossils—Exogyra arietina, Gryphoa Pitcher, Jani 
Teeana, and a small undescribed species of Eatesiee act Me 
Shoal Creek, near Austin, Zxogyra arietina occurs ‘ iid 
greatest profusion, the surface of the ground being som 
literally covered with them of our 
i low, gray 
] 
me of the layers being sp J 
; of Ne- 
* See Remarks on the Tertiary and Cretaceous aie for 
braska, by F. B. Meek and F. V. Hayden, Proc. Ac. N. Proc. Amer: 
May, 1857. Also, Notes on Geol. of Alab., by A. Winchell, 
Assoc., Montreal Meeting. 
