EOCENE TEREBRATULA 
19 
NEW TEREBRATULA FROM EOCENE TERRANES OF 
MARYLAND 
By Prof'. Joseph K. Roberts 
Vanderbilt University, Nashville, Tennessee 
The species of Terebratula occurring in the Aquia formation of 
Eocene age of Maryland is one which heretofore is usually con¬ 
fused with the, Late Cretacic form widely known as Terebratula 
Harlani. The specimens under consideration were collected sev¬ 
eral years ago by Professor Edward W. Berry and Dr. H. P. 
Little from the Aquia formation, three miles west of Leeland, in 
Prince George’s County, Maryland. 
As is well known, Terebratula Harlani was first described by 
Samuel G. Morton,^ from material from the Late Cretacic beds 
of New Jersey which represented, for a long time, the only 
known occurrence of this species. The Morton paper, appearing 
in 1827, differentiates four species of these shells, namely Tere¬ 
bratula Harlani, T. fragilis, T. Sayi, and T. perovalis, of which 
only the first two forms appear to be well founded. There are 
several detailed descriptions of the T. Harlani in the literature 
based upon material from the Rancocas formation of New Jersey 
(Middle Marl of Morton) where it is found in both members of 
that formation. It occurs at the same horizon in Delaware and 
on the Eastern Shore of Maryland, near the Delaware boundary. 
It is erroneously recorded as occurring in the Tertic formation of 
North Carolina. A closely related form is also erroneously re¬ 
corded from the Keokuk limestone of Indiana. 
The most nearly related form is Terebratula Sowerbi Hag. (not 
Nyst, which is T. grandis) of the Senonian of Rugen and Bel¬ 
gium. Throughout the Rancocas formation T. Harlani is one of 
1 Jour. Acad. Nat. Sci. Philadelphia, (1), Vol. VI, pp. 72-75, 1827. 
