410 Discovery of a Skeleton of the Zygodon. 



Our skeleton was discovered on the plantation of Judge Creagh, the 

 same gentleman who forwarded the bones already noticed to Harlan, 

 and from the same neighborhood in which those were obtained. The 

 entire vertebral column is nearly perfect, except two or three of the 

 cervical, which are much broken, and it is possible that others from the 

 same part of the skeleton are lost, since the vertebrae near the head 

 were disjointed and scattered over a sui'face of several feet, but the 

 remaining portion of the vertebral column was in an almost unbroken 

 series to the extreme tail. The entire length of the skeleton, including 

 the head, is nearly seventy feet! Some of the ribs must have been 

 upwards of six feet in length, but of these we only have fragments, in- 

 cluding their extremities and central parts. We have also other long 

 bones belonging to its paddles, as the animal was probably an inhabitant 

 of the water. These are small in proportion to the size of the other 

 bones. The principal organ of locomotion of the animal seems to have 

 been its tail, which is short and thick. Many of the dorsal vertebras 

 are sixteen or eighteen inches long, and upwards of twelve inches in 

 diameter. The transvei'se processes are from three to six inches long. 

 The spinal and also the lateral processes are of about the same length. 

 These last three are united at the base, where they form an arch through 

 which the spinal marrow ran. This arch with the lateral and spinal 

 processes is easily detached from the main body of the vertebrae. The 

 head is much broken, yet we have portions of both jaws with the teeth 

 inserted in nearly a perfect state. The molar teeth are inserted into 

 separate cavities of the jaw by two long roots. The upper portion of 

 these teeth is somewhat hastate, with large and rather blunt serratures 

 on the lower part of the anterior and posterior margins, as in those of 

 the Iguanodon. The average longer diameter of a section of the molar 

 teeth is about four and a half inches. The anterior teeth have a single 

 root, are sharp-pointed, conical, slightly curved, and laterally compress- 

 ed ; the transverse section parallel to the base forming an ellipse. The 

 length of the anterior teeth, including the root, is five or six inches, and 

 the longest diameter nearly two inches. The form of the molar teeth 

 is so peculiar that it is impossible to give a correct idea of them without 

 the aid of plates. 



This Zygodon or Basilosaurus was imbedded in a marly limestone 

 soil. The upper portion, to the depth of one or two feet, is a rich 

 black vegetable mould. Beneath this is a yellowish white marl, yield- 

 ing easily to the mattock, and containing few organic remains. Most 

 of the bones were in this marl from one to six feet beneath the surface. 

 At the depth of about six feet is a green sand or marl resembling the 

 green sand of New Jersey, and containing few organic remains. The 

 vertebral column, as has been before remarked, lay in an almost un- 



