33 SYSTEMATIC PALEONTOLOGY 



A large foramen pierces the inner side of the lateral crest half-way to 

 the superior border, and opposite the middle of the left blow-hole. 



" The dental alveoli are subround, and are separated by narrow septa. 

 They are not deep, the deepest equalling 50 mm., so that the teeth have 

 been easily lost. 



Measuremetits. 



Length of fragment on middle line 800 mm. 



Width of skull at supraorbital notch; left side restored. . .800 



Width of muzzle where broken off 172 



Width of right premaxillary at middle of length 100 



Width of left premaxillary at middle of length 150 



Width of right premaxillary at vomerine keel 100 



Width of left premaxillary at vomerine keel 170 



Elevation of lateral crest above orbit (apex broken off). . . .310 



Length of series of eight teeth 165" 



Cope, 1895. 



Occurrence. — St. Mary's Formation. Drum Point. 



Collection. — Johns Hopkins University. 



Genus ORYCTEROCETUS Leidy. 



Cope in 1867 thus characterizes the genus. " Orycterocetus Leidy. 

 This genus differs from Physeter in the extensive pulp cavity of the 

 teeth, and the absence of the surface cementation." 



Orycterocetus crocodilixus (?) Cope. 

 Plate XYII, Fig. 7. 



Orycterocetjis cornutidens Leidy, 1856, Proc. Acad. Nat. Sci. Phila., voL viii, p. 255. 

 Orycterocetus cornutidens Emmoijs, 1858, Kept. N. Car. GeoL Survey, p. 211, fig. 33. 

 Orycterocetus crocodilimcs Cope, 1867, Proc. Acad. Nat. Sci. Phila., voL xix, p. 144. 

 Orycterocetus cornutidens Leidy, 1869, Jour. Acad. Nat. Sci. Phila., 2nd sen, vol. vii, 

 p. 437. 



Description. — •" This species is based on a tooth belonging to an indi- 

 vidual of one-third or one-fourth the size of the known species, 0. 

 cornutidens Leidy, but nevertheless adult, as attested by the obliquely 

 worn apex of the crown. The general form is that of an elongate curved 

 cone, with flattened sides, and a broad convex face within the curve. 



