FOSSIL FISHES. 265 
state of our knowledge of existing Fishes. The 
inaccessible recesses of the waters they inhabit, 
renders the study of their nature and habits 
much more difficult than that of terrestrial 
animals. The arrangement of this large and 
important class of Vertebrata was the last great 
work undertaken by Cuvier, not long before his 
lamented death, and nearly eight thousand spe- 
cies of living Fishes had come under his obser- 
vation. The full development of their history 
rently shaped feet, armed with nails. Many of these (PI. 26') 
resemble the impressions on the sandstone of Dumfries, and are 
apparently the steps of Tortoises. 
Professor Kaup has proposed the provisional name of Chirothe- 
rium for the great unknown animal that formed the larger foot- 
steps, from the distant resemblance, both of the fore and hind 
feet, to the impression of a human hand ; and he conjectures 
that they may have been derived from some quadruped allied to 
the Marsupialia. The presence of two small fossil mammalia 
related to the Opossum, in the Oolite formation of Stonesfield, 
and the approximation of this order to the class of Reptiles,'which 
has already been alluded to, (page 73, note), are circumstances 
which give probability to such a conjecture. In the Kangaroo, 
the first toe of the fore-foot is set obliquely to the others, like a 
thumb, and the disproportion between the fore and hind feet is 
also very great. 
A further account of these footsteps has been published by Dr. 
Sickler, in a letter to Blumenbach, 1834. Our figure (PI. 26'), 
is copied from a plate that accompanies this letter; on com- 
paring it with a large slab, covered with similar footmarks, from 
the same quarries, lately placed in the British Museum, (1835) 
I find that the representations, both of the large and small foot- 
steps, correspond most accurately. The hind foot (PI. 26"), is 
drawn from one on this slab. PI. 26'" is drawn from a plaster 
