66 bulletin: museum of compakative zoology. 



nearly complete ; (I) the right and left nasals, nearly complete ; (m) a 

 portion of the petrosal 1 ; (n) a portion of the right ramus of the mandi- 

 hle ; (o) several fragments of teeth ; (p) part of an atlas ; and (q) por- 

 tions of three ribs. 



The history of the genus Dorudon has been summarized by Milller, 

 Cams, Leidy, Hay, and others, and it will be unnecessary for me to do 

 more in the present connection than refer to the principal views which 

 have been held regarding it. A list of references will be found in Hay's 

 Bibliography of Fossil Vertebrata of North America, 1902, page 587. 



In the original description, in 1845, Gibbes mentioned that the type- 

 specimen was found " in a bed of green sand near the Santee Canal, in 

 South Carolina. The locality is on the plantation of R. W. Mazyck, 

 Esq., about three miles from the entrance of the canal from the head 

 waters of the Cooper Eiver ... I visited the locality where it was 

 found, but the marling operations of the planters had ceased for the 

 season, and the pits were filled with water. I have made arrangements 

 for excavations in the fall, when I hope to procure other bones of this 

 remarkable fossil " (Proceedings of the Academy of Natural Sciences of 

 Philadelphia, 1845, Vol. 2, pages 254-255). In his second article 

 Gibbes remarked: "During an extensive exploration of the bed of 

 green sand at the locality [where the type was found], with the hope 

 of turning up other portions of the skeleton, fragments of a lower 

 maxilla containing the then unfigured tusk were procured, with twelve 

 caudal vertebrae." (Journal of the Academy of National Sciences of 

 Philadelphia, 1847, series 2, Vol. 1, page 10). 



In this second article Gibbes, influenced by the opinion of Owen 

 (Proceedings of the Academy of Natural Sciences of Philadelphia, 1846, 

 Vol. 3, page 15), abandoned his genus Dorudon, placing the species 

 serratus in the genus Zeuglodon, or Basilosaurus. In 1848 Agassiz 

 (Proceedings of the Academy of Natural Sciences of Philadelphia, 1848, 

 Vol. 4, page 4) expressed the belief that Dorudon was distinct, but 

 the characters which he assigned to it are not intelligible. Leidy in 

 1869 (Journal of the Academy of Natural Sciences of Philadelphia, 1869, 

 series 2, Vol. 7, page 428, Plate 29, figures 2-5) also accepted Dorudon, 

 and gave a list of synonyms of D. serratus, among which are included 

 Zeuglodon brachyspondylus Milller, and Z. hydrarchus Carus, both based 

 on the same specimen. He remarks, however, that it is by no means 

 certain that serratus and brachyspondylus are the same. In this connec- 

 tion Leidy published some figures of teeth from the Eocene of Alabama, 

 which he regarded as belonging to Dorudon. 



