MARYLAND GEOLOGICAL SURVEY 7 



anterior and posterior cutting edge. The serrulations stand from 

 behind, 3-2, 3-2, 3-3, 3-3, the anterior two of the last being very weak. 

 The cutting edge of all these is serrulate. Not only in the number of 

 the crests, but in the more elevated conic apex, do these teeth differ 

 from those of S. holmesii." 



A specimen in the Museum of the Philadelphia Academy of Sciences 

 Ijears the name Basilosaurus atlanticus and purports to come from the 

 Miocene of Maryland. No trace can be found of any description of 

 such a species of Basilosaurus nor does the genus Basilosaurus occur in 

 the Miocene. The label is by Cope and it is probable that it was 

 intended for Squalodon atlanticus. The strong resemblance of the 

 specimens to the teeth of the latter genus bears out this supposition. 



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

 ent river. 



Collections. — The type specimen is in the Museum of the Philadelphia 

 Academy of Natural Sciences. 



Squalodon protervus Cope. 

 Plate X, Figs. 4, 5. 



Cynorca proterva Cope, 1867, Proc. Acad. Nat. Sci. Phila., voL xix, pp. 144, 15^. 

 Cynorca proterva Cope, 1868, Proc. Acad. Nat. Sci. Phila., vol. xx, p. 185. 

 Squalodon protervus Cope, 1869, Proc. Acad. Nat. Sci. Phila., vol. xxi, p. 151. 

 Squalodon protervus Leidy, 1869, Jour. Acad. Nat. Sci. Phila., 2Dd ser., vol. vii, pp. 

 384-423, pi. xxviii, tigs. 18-19. 



Description. — In 1869 Cope gave the following description of this 

 species : " This species is represented in the collection by a single 

 canine tooth, which presents the usual small crown and broad fang of 

 the Cetacea. The fang is, however, shorter than in the ' Colophonodon 

 and Stenodon,' and, with the crown very much compressed in one plane. 

 A shallow groove extends on each side of it to the narrowed and flat- 

 tened truncate base. The tooth is widest at the middle of the fang; 

 the crown is rapidly acuminate, narrow lenticular in section, and fur- 

 nished with a rather thickened postero-internal cutting edge. The 

 anterior or external aspect is worn away b}^ the attrition of a corre- 



'The mollusca collected by Cope at this time and from this locality and described 

 by Conrad were from the Calvert formation. 



