370 The American Geologist. December, 1898 
THE OCCURRENCE OF CRETACEOUS FOSSILS IN 
THE EOCENE OF MARYLAND. 
By RuFUS Mather Bagg, Jr., Ph. D., Colorado Springs, Col. 
Two Cretaceous fossils, Terebratula harlani and Gryphaea 
vesicnlaris, were discovered last summer in the Eocene green- 
sand while the writer was engaged in survey work for the 
State of Maryland. These forms, abundantly and character- 
istically developed in New Jersey, have been supposed to be- 
long exclusively to the Cretaceous and so far as I am able to 
learn there is no record of their occurrence in post-Creta - 
ceous deposits, if we except the doubtful report of the presence 
of Terebratula harlani in the Tertiary of South Carolina. 
One of these fossils, Terebratula harlani, is in New Jersey 
confined to a narrow but definite zone of the Rancocas forma- 
tion (Middle Marl bed) which averages only two feet in thick- 
ness and extends in a northeast-southwest direction across the 
entire state. The other, Gryphsea vesicularis, while found in 
all portions of the Monmouth formation, is, in the Ranocoas. 
limited to another definite zone beneath that of Terebratula 
harlani. 
The specimens of Terebratula harlani which the author 
discovered in Maryland were found in the Eocene marl of 
Prince George's county in a bank by the roadside on Western 
branch of the Patuxent river about three miles west of Lee- 
land, a small station on the Popes Creek railroad. The green- 
sand at this cutting in the road is very fossiliferous and carries 
the common lower Eocene fauna, Ostrea compressirostra Say, 
Cucullaea gigantea ' Conrad, Cytherea ovata Rogers, and 
several others. 
The Terebratulae under discussion occur in the lower por- 
tion of the bank about eight feet above the bend of the road. 
They seem to have a limited vertical range of about five feet 
and are often grouped together in indurated lenses of the 
marl but they are by no means confined to these indurations. 
The shells are remarkably well-preserved, very large and 
thick, and many of them attain a maximum size for the 
species of two and three-quarters inches in width by three 
inches in length. These forms so closely resemble New Jersey 
