EXTINCT MAMMALIA OF NORTH AMERICA. 427 



The posterior border is embraced by an attempt to form a basal cingulum. The en- 

 amel of the crown is nearly uniformly corrugated, and the wrinkles are much 

 interrupted. The fang, broken at its point, has been about twice the length of the 

 crown, is conical, sliglitly curved, and feebly gibbous. 



The tooth bears some resemblance to the corresponding ones of the Californian 

 Seal, Arctocephcdus inonteriensis, and may perhaps belong to a Seal. It approximates 

 in appearance one of the specimens (figure 9, plate XXX) from Charles Co., Md., 

 referred by Prof Cope to Squalodon mento. It differs, however, in the proportionately 

 greater breadth of the crown, and in possessing acute borders, and an internal 

 swollen base. The enamel is also generally more strongly corrugated. The fang is 

 much shorter, and very much less gibbous. Side by side the two teeth do not appear 

 to belong to the same animal. 



The measurements of the specimen are as follow : 



Length of the crown, 6 lines ; breadth, 5 lines ; thickness, 4 lines. 

 Length of the fang restored, 14 lines ; breadth, 4J lines. 

 Length of the tooth restored, 19 lines. 



BASILOSAURUS. 



Basilosanms cetoides. 



Gigantic bones, Logan : Proc. Geol. Soc. Lond. (1827, 8) 1834, I, 85. 



Badlosaurus, Harlan: Bui. Soc. Geol. de France (1833), 1835, IV, 124; Trans. Araer. Phil. Soc. 

 1834, IV, 397, PL XX, Figs. 1, 2; Edinb. NewPhilos. Jour. 1834, XVIII, 29; Trans. Geol. 

 Soc. Penn. 1835, I, 77, 348, PL XXII— XXIV ; Med. Phys. Res. 1835, 337, 349, Pis. XXVI 

 -^XXVIII; Pr. Geol. Soc. Lond. (1839) 1842, III, 23; Bui. Soc. Geol. de France, 1839, X, 

 89 ; Lond. and Edinb. Philos. Mag. 1839, XIV, 302 ; Trans. Geol. Soc. Lond. (1839) 1842, 

 VI, 67. Owen : Pr. Geol. Soc. Lond. (1839) 1842, III, 24 ; Lond. and Edinb. Philos. Mag. 

 1839, XIV, 302. Wailes : Rep. &c. Geol. of Missis. 1854, 277. 



Zeuglodon, Owen: Proc. Geol. Soc. Lond. (1839) 1842, III, 24; Lond. and Edinb. Philos. Mag. 

 1839, XIV, 302. Conrad: Am. Jour. So. 1840, XXXVIII, 381. Anon. : Amer. Jour. Sc. 

 1845, XLIX, 218. Meyer : Jahrb. f. Min. 1847, 669. Hale : Am. Jour. Sc. 1848, VI, 361 . 



Zeuglodon cetoides, Owen : Lond. Edinb. Philos. Mag. 1839, XIV, 302 ; Trans. Geol. Soc. Loud. 

 1841, VI, 69, Pis. VII— IX ; Palteontology, 1859, 345 ; Pictet's Traite de Paleout. 1844, 

 317. Mantell : Medals of Creation, 1844, 826. Emmons : Am. Quar. Jour. Agric. 1845, II, 

 59, 366 ; 1846, III, 223, Pis. I, II. Buckley : Am. Jour. Sc. 1846, II, 125, Figs. 1, 2. Gei- 

 nitz: Versteinerungskunde 1846, 56. Miiller : Monatsb. d. Akad. Wissens. Berlin 1847, 103. 

 Archiv f. Anatomic, 1847, XIV, 363, 377, 378. Carus : Nov. Act. Acad. Nat. Cur. 1850, 

 XXII, 381. 



Zeuglodon Earlani, Dekay : Nat. Hist. New York, Zool. 1842, 123. Wailes : Rep. &c. Geol. 

 Missis. 1854, 278. 



Zygodon, Buckley : Am. Jour. Sc. 1843, XLIV, 409 ; Edinb. New Phil. Jour. 1843, XXXV, 77. 

 Koch : Jahrb. Min. 1845, 676, in part. 



Eydrarchus Ilarlani, iu part of Koch : Kurze Beschreib. d, Ilydr. Ilarl. 1846 ; Jahrb. f. Min. 



