Mesozoic and Cenozoic Geology and Paleontology. 30 
California, Delphinus occidwus; from Washington county, Texas, An- 
chippus texanus; from the Bad Lands of Nebraska, Lophiodon occiden- 
tale, and from Shark river, Monmouth county, New Jersey, Anchippo- 
dus riparius. 
T. A. Conrad* described, from the Miocene of the Atlantic coast, 
Volutella oviformis, Prunum virginiana, now. Marginella virginiana, 
Mercenaria cuneata, Caryatis plionema, Carditamera recta ; and from 
Wyoming, Goniobasis cartert. 
Prof. O. C. Marsh} described, from the Tertiary at Antelope station, 
on the Union Pacific Railroad, 450 miles west of Omaha, in Nebraska, 
Hquus parvulus, now Protohippus parvulus. 
The Tertiary underlies a wide central belt in West Tennessee, and 
was subdivided by Prof. Safford,{ in 1869, in ascending order, into 1, 
Porters’ Creek Group ; 2, Orange Sand; 3, Bluff Lignite ; 4, Post- 
pliocene beds, on the Mississippi Bluff, consisting of Bluff gravel and 
Bluff loam ; and superficial gravel beds, in other parts of the State, 
consisting of ore-region gravel, eastern gravel, and lastly of bottoms, 
and alluvial beds. 
The Bluff lignite consists, especially in the middle and southern 
parts of the State, ofa series of stratified sands, with more or less 
sandy, slaty clay, characterized by the presence of well-marked beds 
of lignite; though, in the northern part of the State, its upper portion 
is frequently more or less indurated, presenting layers of soit sand- 
stone with less lignite. The upper part of the series is generally well 
exposed below the gravel of the Mississippi Bluffs. At Memphis, how- 
ever, it scarcely appears above low-water. About one hundred feet 
of the series has been seen. . In this thickness it contains from one to 
three beds of lignite, which are from half a foot to four feet in 
thickness. 
The outcrop of the Orange sand or Lagrange Group, forms more 
than athird of the entire surface of West Tennessee. It occupies a 
belt, about 40 miles wide, which runs in a northeasterly direction, 
through nearly the central portion of this division of the State. As 
seén in bluffs, railroad cuts, gullies, and in nearly all exposures, it is 
generally a great stratified mass of yellow, orange, red or brown, and 
white sands, presenting occasionally an interstratified bed of white, 
* Am. Jour. Conch., vol. iv. 
ft Am. Jour. Sci. & Arts, 2d series, Vol. xlvi. 
t Geo. of Tenn. 
