420 EXTINCT MAMMALIA OF NORTH AMERICA. 



willi the ni()I:ir teeth. In their comparative smoothness and size they bear a nearer 

 relation with the representation of" a niohir tooth o^i Squalodon pygmceus, and perhaps 

 belong to that species. 



Squalodon pelagms. 



A small species, indicated by the fragment of a jaw, from Ashley River, near 

 Charleston, South Carolina. The specimen was obtained by Prof. F. S. Holmes, who 

 attributes it to the eocene formation. 



The fragment represented in figure 1, plate XXIX, is from the intermediate portion 

 of the jaw, and contains a molar tooth, two alveoli and part of another. The first alve- 

 olus of the specimen is fore and aft oval, four lines by three lines, and contained the 

 last of the premolars, or a transitional tooth with connate fangs. The succeeding 

 alveolus accommodated a tooth with a distinct pair of fangs. The tooth remaining 

 in the specimen occupied the next alveolus. It has a laterally compressed conical 

 crown, with the breadth greater than the length and the thickness less than half the 

 former measurement. The borders are trenchant and devoid of denticles. The sur- 

 fiices are longitudinally rugose near the base, especially internally, and externally 

 there is a feeble tendency to the production of a basal ridge. The fangs are distinct. 

 The molars were separated by interspaces rather greater in breadth than the teeth, 

 and the outer part of the intervals exhibit moderately deep concave fossse, for the 

 accomrnodation'of the opposed teeth when the jaws are closed. 



The length of the fragment, corresponding with the position of four teeth, is about 

 three and one-half inches. The crown of the remaining tooth has been about four 

 and one-half lines long and its width is five lines. 



Squalodon pygmseus. 



Zeuglodon, Tuoniey : Proc. Ac. Nat. Sc. 1847, III, 151 ; Jour. Ac. Nat. Sc. 1847, I, 16 ; Am. 



Jour. Sc. 1847, IV, 283; Rep. Geol. South Carolina, 1848, 166; 1849, VIII, 69. Gibbes : 



Jour. Ac. Nat. Sc. 1847, 1, 8. Holmes : Am. Jour. Sc. 1849, VII. 

 Badlosamrus, Tuomey : Jour. Acad. Nat. Sc. 1847, I, 16, PI. V. Holmes : Am. Jour. Sc. 1849, 



VII. 

 Zeuglodon pygmccus, Miiller: Monatsb. Ak. d. Wis. Berlin, 1851, 242; Zeuglodouteu v. Nord- 



amerika, 1849, 29, PI. XXXIII, Figs. 1, 2. Bronn : Lsth. Geog. 1853-6, III, 771. 

 Basilosaums pygmceus, Leidy : Anc. Fauna Neb. 1853, 8. 

 Doryodon pygmccus, Cope : Proc. Ac. Nat. Sc. 1867, 155. 

 Doryodon, Cope : Proc. Ac. Nat. Sc. 1868, 186. 

 PJiocodon Holmesii, Agassiz : In an unpublished Plate. 



This species was established upon a mutilated skull, obtained by Profs. F. S. 

 Holmes and L. R. Gibbes from the eocene formation of Ashley River, about ten miles 

 from Charleston, South Carolina. A brief description, accompanied by a rude sketch 

 of the specimen, was published by Mr. Tuomey in the Proceedings and Journal of 

 this Academy, as above indicated. Mr. Tuomey referred the fossil to the genus Zeu- 



