Petrlfadiions found in St. Peter’s Mountain . 455 
iricht. A, B, C, D. is the body ; C, I, K, E, F. the fpinous 
procefies; C, K, I. the medullary canal, running under 
K, E, F, in a direction parallel to IF, and coming out again 
at F. The remaining marks of the lamellated epiphyfes I, D. 
and A, B. are evident proofs of the analogy between thefe and 
the vertebrae of the cetaceous fifhes ; and alfo of their want of 
refemblance to the vertebrae of the crocodile, as will appear by 
comparing, the firfl and fecond figures with the fifth. 
Fig. 6. Is a very accurate drawing of one of the foflil 
teeth belonging to the fame incognitum. A B C. is its point* 
of a lanceolated figure, whofe edges B A* and A C, are 
dentated ; B C, is the root, uneven,, bony, fixed within the 
focket with D, G, F. ; D, G, B, C. is covered with the gums % 
H, I. is an oval finuofity, in which generally the fecondary 
teeth are generated, as is feen in tab. XVT. reprefenting 
a fragment of the upper jaw-bone of the lame incognitum r 
A, B, C, D, E. 
The teeth in all the Phyfeteres and Delphini have folid roots, 
except in the young ones, in which they often have cavities to 
receive the blood- veffels and nerves. But the crocodile has the 
teeth intirely hollow, as appears in 
Fig. 7. in whiclr the cavity 1 IT, A, 0 , Ihews the difference 
between the crocodile’s teeth and thofe of the cetaceous and 
other fifhes. This tooth is the anterior one of a large head of 
a crocodile, two feet long, and of the fame fize as that in the 
Britifh Muleum. A hollow tooth may notwithfianding be- 
long to a Phyfeter, as Dr, Otiio Fabricius obferves in his 
Fauna Groenlandica, p. 44. when fpeaking of the Phyfeter 
microps : of whicii he fays* 44 Habetin maxilla inferiori dentes 
