Bibliographical Notices. 171 
As in the attempted delineation of the older rocks of Arkansas, so 
also in the supposed area of the Cretaceous strata, the published maps 
are very incorrect. ‘I have not been able to detect (says Dr. Owen) 
any symptoms of Cretaceous strata, even in deep wells, any further 
north in Arkansas than Clark county, about two and a quarter miles 
north-west of Archidelphia, 7. e. near the line between townships 7 
and 8 south, in about latitude 34° 6’. At the fine section exposed 
on the Arkansas River, at the ‘ White Bluffs,’ z.e. about latitude 
34° 27', beds of Quaternary date occupy the higher part of the 
bluff, while the lower 50 or 60 feet, extending down to the low-water 
mark of the Arkansas, is most decidedly Tertiary shell-marl of 
Eocene date, affording the following species:—Cardita densata, 
Fusus magnocostatus, F. Fittonii, Corbula Alabamensis, Monoceros 
vetustus, and others undetermined. Even at a point on the river- 
bank where a considerable disturbance and tilting of the strata are 
conspicuous, nothing lower in the geological series can be seen than 
Eocene Tertiary.” 
In Southern Arkansas immense numbers of very large oyster-shells 
lic strewn on the ploughed lands, where the Cretaceous strata come 
to the surface—Ewogyra costata, sometimes weighing upwards of 
four pounds, and Ostrea vesicularis, These are collected and made 
into a superior lime. Bones of sharks and saurians are also found. 
Dr. Koch collected many bones here, and removed them to Berlin. 
Two plates (7 and 8) of Cretaceous fossils, some of which are un- 
described, accompany the Report. 
The Tertiary beds are best seen in section at the White Bluffs : 
they yield some limestone for lime-burning, and abundance of shell- 
marl, good for manure ; also, in some places, gypsum, large masses 
of iron-ore, and thick beds of lignite. The last, as well as some 
lignites occurring in the Quaternary deposits, yield, by distillation, 
from thirty to forty-five gallons of crude oil to the ton of 2000 Ibs. ; 
and for this purpose the-lignites are likely to be more profitable than 
as fuel. A plate illustrating the kind of leaves (of dicotyledonous 
trees) found in the Tertiary lignites of the ‘‘Chalk-banks” of the 
Mississippi and the red shales of Tennessee is given by M, Lesquereux 
(pl. 6), who here figures and describes three new species of Magnolia, 
Quercus, and Rhamnus. Plate 9 illustrates some of the Tertiary 
shells and fish-teeth. 
To the Drift or Quaternary age are referred numerous and exten- 
sive drift-deposits, composed mostly of quartz, sandstone, and hard 
shales and slate ; sometimes these are very thick, consisting of coarse 
material, and containing large blocks. These Drifts have no con- 
nexion with the Northern Drift, though possibly partly contempora- 
neous with it; but have been due, in Dr. Owen’s opinion, to the 
repeated and long-continued movements of the rocks one upon an- 
other, during periods of disturbance and upheaval ; and some of the 
Drift may be “‘of comparatively recent date, perhaps as new as the 
date of the rise of the Quaternary beds of the Western States out of 
the great lake-like expansions of fresh water in which they were 
accumulated.” 
