GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



357 



was incapable of progression on land, and refers to the 

 tail as the chief means of locomotion. 



Dimensions — Total lengthy, sixteen inches ; circumfe- 

 rence, immediately below the neck, eleven and a half 

 inches 5 depth at the same place, three inches; breadth, 

 four inches; breadth taken at the external condyle, five 

 and a half inches. The extreme accuracy with which 

 this bone has been represented, renders further detail 

 ini necessary. 



Tihia. PL 23, fig. 1. 



We have represented a portion of the long bones of 

 the extremities, five inches in length, which can be re- 

 ferred to none other than the inferior extremity of the 

 tibia : like the same bone in the human subject, it en- 

 larges near its distal extremity, and is furnished with an 

 internal and external malleolus. The tarsal articulating 

 surface is small, and appears more adapted for the con- 

 nexions of a foot than a paddle. This bone is of a solid 

 structure, leaving but a small cavity in its centre for a 

 medullary canal. Greatest circumference, seven and a 

 half inches. 



The collection in the cabinet of the A. N. S. includes 

 a portion of the head of a femur, the circumference of 

 which, in the antero- posterior direction, was, before frac- 

 ture, twenty inches; transverse circumference, thirteen 

 inches. A very small portion of the neck remains at- 

 tached.* 



A letter has just been received from the Hon. Mr Creagh, dated May 

 29th, 1835, announcing the discovery and partial disinterment of another 

 skeleton of the Basilosaurus ; and assuring us of his determination to forward 

 a large collection of these remains during the ensuing winter. 



