MAIiVLAND c;i:ui,UtiICAL SLUN KY OT 



Order Tl^STUDHNATA. 

 SiibordcT CRYITODIkA. 



Family CHIM.ONIIDAH. 



(k-iius I-UCLAS'IHS Coj-e. 

 EUCLASTHS (?) S|). C'liirk. 



Plate X, Fig. 7. 



Kuclastea {?) sp. Clark, 1895. Johns Hopkins Univ. Circ, vol. xv, No. 4. 

 Endaslex (.-') nj). Clark, 181)6. Bull. 141, U. S. Geol. Survey, p. .59. 



Description. — "Several I'l'auiiicnts t'nim (lie carapace of a large sea 

 turtle were found at C'lifloii llcacli. Imt tliey were not sufficiently well 

 preserved to identify the genus with certainty. Fragments of the costals 

 show that the surface was smooth and the edges of the plate more or 

 less rounded. The sliields were relatively thin."' Clark, 1895. 



Occurrence. — Aquia Formation. Clifton Beach. 



Collection. — Johns Hopkins University. 



Suborder TRIONYCHIA. 



Family TRIONYCHIDAE. 



Genus TRIONYX GeolTroy. 



Teionyx virgixiaxa Clark. 

 Plate XI, Figs. 1, 2. 



Triouyx virginiaiia Clark, 189.5. .Johns Hopkins Univ. Circ, vol. xv, No. 4. 

 Trionyx virglmaua Clark, 1890. Bull. 141, U. S. Geol. Survej', p. -59, pi. viii, figs. 

 la and lb. 



Description. — Fragments of costals with tuherculated and ridged sur- 

 faces, characteristic of the genus Triony.v. The longitudinal ridges are, 

 prominent, at times irregular and inosculate; relatively remote and 

 separated by intervals of about twice their width; generally entirely 

 disappear near the margins of the plates. 



Length of the largest fragment 130 mm., width 1.5 mm., thickness 

 18 mm. 



