MARYLAND GEOLOGICAL SURVEY 65 



Later, about 1895, Cope was again of the opinion that the genus 

 Thecacliampsa should stand. In consultation with Dr. W. B. Clark in 

 regard to the preparation of the latter's Bulletin on the Eocene deposits 

 of the Middle Atlantic S^"ates he was, according to Dr. Clark, " dis- 

 tinctly of mind that the genus should be called Thecacliampsa instead 

 of Crocodilus.^' 



In the same article in which T. sicaria was described. Cope gave the 

 following synopsis of the species of Thecacliampsa: 



"Crowns of teeth not compressed, with, short cutting- edges ....T. antiquus 



(C. antiquus L.) 

 Crowns cylindric, curved, with long- and delicate cutting edges . . T. sericodon. 

 Crowns compressed, with very long crenulate cutting edges, on a marginal 



base T. sicariay 



Thecachampsa (?) SERICODON Cope. 

 Plate XXVII, Figs. 1, 2. 



Thecachampsa? sericodon Cope, 1867, Proc. Acad. Nat. Sci. Phila., vol. xix, p. 143. 

 Thecachampsa sericodon Cope, 1869, Proc. Acad. Nat. Sci. Phila., vol. xxi, p. 13. 

 Thecachampsa sericodon Cope, 1869, Amer. Nat., vol. iii, p. 91. 

 Thecachampsa sericodon Cope, 1871, Trans. Amer. Philos. Soc, vol. xiv, p. 64, pi. v, 



figs. 7 and 8. (Pp. 1-104 appeared in 1869.) 

 Thecachampsa sericodon Cope, 1875, Proc. Amer. Philos. Soc, vol. xiv, p. 363. 

 Thecachampsa (Crocodilus) sericodon Cope, 1883, Amer. Nat., vol. xvi, p. 984. 

 Thecachampsa sericodon (?) Case, 1901, Md. Geol. Survey, Eocene, p. 9.5, pi. x, fig. 3. 



Description. — This species was based " on a number of specimens 

 of elongate conic crowns, which resemble to a considerable extent those 

 of Crocodilus antiquus Leidy, of the same epoch. They differ from 

 T. contusor in their more compressed and elongate form, the presence 

 of a subacute ridge on the apical three-fifths of the crown, the absence 

 of the lateral grooves, and the chevron structure. They are, on the 

 contrar}', minutely striate, and possess a silky lustre. 



"Length of the medium specimen 16.5 lines (23 mm.); base of the 

 crown 9 lines (18 mm.)." 



Occurrence. — Calvert Formation. Charles county near the Patux- 

 ent river. 



Collections. — The type specimens, two teeth, are in the museum of 

 the Academy of Natural Sciences of Philadelphia. 



