96 SYSTEMATIC PALEONTOLOGY 



Thecachampsa contusok Cope. 

 Plate X, Fig. 4. 



Thecachampsa contuaor Cope, 1867. Proc. Acad. Xat. Sci., Pliila., p. 143. 



Description. — This species was recognized by Cope as of doubtful 

 value and he considered the forms placed here as possibly belonging to 

 T. antiqna. A specimen in the collection has the characters assigned 

 to coniusor except that the section of the base is elliptical instead of 

 rounded, and certainly does not belong to antiqua, so that it may be 

 placed here provisionally. 

 . Occurrence. — Aquia Foematio?^. Aquia Creek. 



Collection. — Maryland Geological Survey. 



Thecachampsa maPlYlaxdica Clark. 

 Plate X, Fig. 5. 



Thecachampsa marylandica Clark, 189.5. Johns Hopkins Univ. Circ, vol. xv, p. 4. 

 Thecachampsa marylandica Clark, 1896. BulL 141, U. S. Geol. Survey p. .58. pi. 

 vii, fig. 1. 



Description. — The specimen is a fragment of the jaw, described as 

 ^' moderately thick, the single complete and one partially preserved 

 alveoli not far removed from one another. Teeth with elongate, 

 slightly curved, conic crowns; basis circular, its diameter about one- 

 third the length of the tooth; apex acute, circular; surface with fine 

 prolongations and striations." Clark, 1895. 



Dimension of the tooth 38 mm., diameter at base 12 mm. 



Occurrence. — Aquia Foematiox. Clifton Beach, Upper Marlboro. 



Collections. — Johns Hopkins University, Maryland Geological Survey. 



COPEOLITE. 



Plate X, Fig. 6. 



CoproUte Clark, 189.5. Bull. 141, U. S. Geol. Survey, p. 60, pi. vii, fiy-. 4. 



Description. — A reptilian coprolite of very perfect form. It is only 

 one-half preserved. These coprolites are rather common in the forma- 

 tion. 



Occurrence. — Aquia Foematiox. Clifton Beach. 



Collection. — Johns Hopkins University. 



