LECTURE VIII. 
^1 
I shall proceed to give a view of the Linnaean 
arrangement of the different kinds of Fishes. In 
order to understand this we must observe that 
the under or belly fins, called by Linnaeus the 
ventral fins, are to be considered as analogous to 
the feet in quadrupeds ; and it is from the si- 
tuation, presence or absence of these fins that the 
Linngean divisions of fishes are instituted. 
Such fishes as are entirely destitute of ventral 
fins are termed apodal or footless fishes, and 
these form the first Linncean order.' Those which 
have the ventral or belly-fins placed more forward 
than the pectoral or breast-fins, are termed ju- 
gular fishes, and form the second Linnasan di- 
vision. Those which have the ventral fins situated 
directly or immediately beneath the breast fins 
are called thoracic fishes, and constitute the third 
Linnaean division ; and lastly those which have 
the ventral fins situated beyond or behind the 
breast or pectoral fins are termed abdominal 
fishes, and form the fourth Linnaean division. 
There still remains a particular tribe called 
cartilaginous fishes. This is the tribe which Lin- 
naeus improperly admitted among his amphibia, on 
a supposition of their being furnished with lungs 
