106 STSTEilATIC PALEOXTOLOGY 



Description. — Teeth scarcely distinguishable from those of 0. elegans 

 except by their slightly smaller size and by the absence of strias upon 

 the inner coronal face. Anterior teeth much elevated and narrow, but 

 moderately stout. Lateral denticles of both anterior and lateral teeth 

 occasionally flanked by a smaller secondary pair. 



Teeth belonging to this species accompany those of 0. elegans and 

 0. macrota in various localities of Maryland and Virginia, but are less 

 numerous than either of these forms. From the Miocene of this state, 

 very few examples have been obtained. In some specimens two well- 

 developed pairs of lateral denticles occur, as shown in Plate XIV, Fig. 1, 

 and also in Figs. 8Ga and 87a of Emmon's Xorth Carolina Geological 

 Survey Eeport (1858), p. 241. 



Occurrence. — Nanjemoy Foematiox. Popes Creek, Woodstock. 

 Aquia Foemation. Mattawoman Creek, Fort Washington, Liverpool 

 Point. 



Collection. — Maryland Geological Survey. 



Genus OTODUS Agassiz. 

 Nearly all the species assigned by Agassiz to this genus have been 

 distributed by subsequent authors among Lamna, Odontaspis and 

 Oxyrliina. ISToetling even goes so far as to refer the type-species 

 0. obliquus, to the genus Carcharodon, although the coronal margin is 

 never distinctly serrated. The best modern opinion is that the pecu- 

 liarly robust teeth belonging to this species should be provisionally re- 

 tained in the place provided for it by its founder, and along with this 

 should he ranged a second, somewhat smaller species occurring in Eng- 

 land and Eussia, known as 0. trigonalis (Jaekel). 



Otodus obliquus Agassiz. 

 Plate XV, Figs. 1-lc. 



Otodus obUqnwi Agassiz, 1843. Poiss. Foss., vol. iii, p. 267, pi. xx.xi, pi. xxxvi, 



figs. 22-21. 

 Otodus oblifpms Gibbes, 1849. Jour. Acad. Nat. Sci. Phila., 2iul ser., vol. i, p. I'.t'.t, 



pi. xxvi, figs. 131-1.37. 



Lamna acuminata Gibbes, 1849. Loc. cif., p. 197, pi. xxv, figs. 113, 114 (? not fig. 



115). 

 Lamna {?) ohlirjua Clark, 189.5. Johns Hopkins Univ. Circ, vol. xv, p. 4. 

 Lamna {?)ohUqua Clark, 1890. Bull. 141, U. S. Geol. Survey, p. Ol. 

 Otodus obliquus Woodward, 1899. Proc. Geol. Assoc, vol. xvi, p. 10. 



