1846.] Bones of the Zeuglodon. 227 



their sockets; fig. 4, a, shows a wide space which exists between 

 the two remaining canine teeth, between which there is a fossa h, 

 tor the reception of the superior canine; the superior tooth when 

 the mouth was closed, shut upon the outside of the lower jaw. 

 A deep groove passes longitudinally along the centre of the jaw, ]^ 

 inches deep, and 1;^ wide. This portion of the jaw is 15 inches 

 long, and 4 inches thick at the largest end. The shape of this 

 piece proves that the Zeuglodon had a very long narrow snout, 

 and comparatively high; and in this respect is unlike the aligator 

 of this country, which is rather broad and flat. Fig. 2, side view; 

 iig. 4, front view. 



Fig. 1. Tibia ? — This bone seems to be a tibia, with the large 

 end broken and lost. Lower articulating surface, as w^ould be 

 expected, oblique and flattened towards the tarsal extremity; 

 length, 14 inches; breadth, at the flattened part, 3|. It has a 

 ridge posteriorly, for the insertion of muscles. Although this 

 bone is broken, and its head missing, there are two perfect heads 

 of the hmneri among the bones, which judging from their size 

 would be considered applicable to this bone; their broken sur- 

 faces do not, however, fit each other, and the form of this long 

 bone seems to indicate that it is a tibia rather than a humerus. 

 This is particularly indicated by the sharp and tolerably high 

 ridge along its posterior part. 



Humerus. — Figs. 5, 7. This a short thick bone, flattened at 

 the inferior part; lower articulating surface broken and absent. 

 Length of the remaining part, 13^ inches; diameter of the flat- 

 tened part, 5 inches; diameter at the head, 6 inches. The head 

 of this bone when inserted into the acetabulum is evidently far 

 too small, and there can be no doubt that it is a humerus, rather 

 than the femur; and, besides, the parallelism of the head with the 

 shaft of the bone very clearly designates the position it occupies 

 in the skeleton. 



Cervical Vertebra. — Fig. 6. The cervical bones are broken; 

 they were enveloped but partially in the matrix, and hence have 

 been exposed to injury; transverse diameter of the body, 6 inches; 

 perpendicular 3.^- inches, and rather sharply rounded. Length of 



