LECTURE VIII. 51 



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 

 Linnasan 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 Linnaean 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 Linnaean 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 Linnsean 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 



