206 The Aiiicricaii Gcoluijist. April, 1895 
Louisiana bounded in a general way by the Arkansas and 
Texas lines, by the Ouachita river as far south as Harrison- 
burg, by a line running thence to Alexandria on the Red 
river, and thence northeast to a point west of Mansfield on 
the Sabine river. This study was l>egun in the fall of 1889; 
in 1892 it was the good fortune of the author to be assistant 
to Dr. Otto Lerch in his survey of the hills of northern Lou- 
isiana. From the fall of 1892 to the sjiring of 1894, while a 
student at Harvard University, I devoted a large portion of 
my time to preparing a report on the Eocene fossils of Louis- 
iana. During the autumn of 1894, acting under instructions 
from the Director of the United States Geological Survej^ the 
author returned to Louisiana to collect more fossils and to 
study further the general geology of the region. In the re- 
port for this Survey much more detail will be given than is 
here presented, and lists of the fossils with descriptions and 
figures of the new species will be included. 
This area has been the subject of study by several able ge- 
ologists, ("onrad as early as 1834* announced the existence 
of Eocene in Louisiana from fossils sent liim. Later Hilgard, 
Hopkins, Johnson, Lerch, Harris, and McGee, have done field 
work in that state. The publications f)f these geologists will 
be alludetl to as reference to their work becomes necessar3\ 
The Ghetaceols. 
The existence of Cretaceous strata in I^ouisiana was first 
indis])utably established by Hilgard in 1869. f Subsequently 
Hopkins, Johnson, and Lerch, have noted the occurrence of 
Cretaceous in that state. Dr. Lerch gives a list of the locali- 
ties of these rocks on page 72, part 2, of his "Preliminar}^ Re- 
port upon the Geology of the Hills of Louisiana." Cretaceous 
outcrops have been found in the following parishes in nortli- 
ern Louisiana : Webster, Bienville, Natchitoches, Winn and 
Rapides. 
Hilgard observed that these outcrops when mapped form a 
line trending from northwest to southeast.;). Associated with 
the outcrops of the Cretaceous are salt deposits; hard lime- 
*J()urii;il Ac;id. Nat. Sci., Phila., vol. vri. p. 120, 18:54. 
fPiiHc 11, Preliminary rcpoi-tof a (icological Reconiioissaiicc of Lou- 
isiana, in DcHow's New Orli-ans Review, Sept. 1H()!). 
top. cit., pa ye 11. 
