52 
LECTURE VIII. 
as well as with branchiae or ramified gills. This 
division differs from all the rest of the fish tribe in 
having a cartilaginous instead of a bony skeleton, 
and in being destitute of ribs. It consists of the 
Lampreys, the Rays, the Sharks and a variety of 
other fishes, and will be particularized after our 
survey of the Linn^ean fishes, or such as have a 
bony skeleton, furnished with ribs. 
In passing through these I shall select a genus 
or two of each division as an example, and parti- 
cularize a few of the leading or principal species. 
Of the first division or the apodal or footless 
fishes, in which the ventral or belly fins are want- 
ing, the genus Murcena or Eel is one of the princi- 
pal. The Eels are distinguished by their long 
clyindric smooth body with a shallow back-fin, 
imitii'ig with that of the tail into a continued bor- 
der; tubular nostrils, and eyes covered by the 
common or general skin, which is transparent in 
those parts. The Common Eel, which is so w^ell 
know 11 as scarcely to require a particular descrip- 
tion, is a very general inhabitant of almost all parts 
of the ancient continent, varying in size and co- 
lours according to the nature of the waters in 
which it is found. I have before observed that it 
