MARYLAND GEOLOGICAL SURVEY 79 



Collections. — Maryland Geological Survey, Johns Hopkins University, 

 Philadeljjhia Academy of Natural Sciences, Museum of Comparative 

 Zoology. 



Odontaspis elegans (Agassiz). 



Plate XXX, Figs. 3a, 2b, 3. 



Lamna elegans Agassiz, 1843, Poiss. Foss., voL iii, p. 369, pL xL 6, fig. 24, (non pL 



XXXV, figs. 1-7, itec pi. xxxvii a, figs. 58-59). 

 Odontaspis elegans Eastman, 1901, Md. Geol. Survey, Eocene, p. 104, pi. xiv, tigs. 



2a, 2b, 2c, 3a, 3b, 3c. 

 Lamna elegans Hay, 1902, Bull. 179, U. S. Geol. Survey, p. 303. 



Notwithstanding this is the most abundant of all sharks' teeth in 

 the Eocene of Maryland and adjoining states, it is extremely uncommon 

 in the Miocene. It is recorded by Cope from the Miocene of Charles 

 county in this state, and from Cumberland county. New Jersey, but no 

 examples are preserved in the Museum of the Philadelphia xA.cademy 

 of Natural Sciences with the rest of the Thomas Collection, which 

 formed the basis of Cope's report. The dozen or so of specimens 

 obtained by the Survey are all from Plum Point, and were found com- 

 mingled with teeth of the preceding species. 



Occurrence. — Calvert Formation. Plum Point. 



Collection. — Maryland Geological Survey. 



Gerus OXYRHINA Agassiz. 

 This genus is distinguished from Lamna by the prevailing absence 

 of lateral denticles in the teeth, and as shown by several nearly com- 

 plete skeletons from the Upper Cretaceous of this country and Italy, 

 has remained practically constant from Mesozoic time to the present. 



OXYRHINA DESORII AgaSSiz. 



Plate XXX, Fig. 4. 



OiyrMna desorii Agassiz, 1843, Poiss. Foss., vol. iii., p. 282, pi. xxxvii, figs. 8-13. 

 Oxyrhina desorii Gibbes, 1847, Proc. Acad. Nat. Sci. Phila., vol. iii, p. 267. 

 Oxyrhina desorii Gibbes, 1840, Jour. Acad. Nat. Sci. Phila., 2nd ser., vol. i, p. 203, 



pi. xxvii, figs. 169-171. 

 Oxyrhina wilsoni Gibbes, 1849, Jour. Acad. Nat. Sci. Phila., 2nd ser., vol. i, p. 303, 



pi. xxvii, figs. 172, 173. 

 Oxyrhina desorii Emmons, 1858, Kept. N. Car. Geol. Survey, p. 236, fig. 67. 

 Isurus desorii Hay, 1902, Bull. 179, U. S. Geol. Survey, p. 305. 



