LECTURE VIII. 
81 
One of these is the Diodon Hystrix, or Porcu- 
pine-Fish, which grows to the length of about 
a foot and half, and is covered over with a strong 
skin, beset with very long and sharp-pointed 
spines, so that in point of habit or external ap- 
pearance it may be said to connect in some de- 
gree the class of fishes with that of the spiny 
quadrupeds, such as the Porcupines and Hedge- 
hogs. Another species has shorter spines with a 
much broader base. 
There is a very remarkable European fish, 
sometimes referred to this genus, but which in 
reality should form a distinct one, commonly 
called the Sun-Fish or Diodon Mola, It is of 
a silvery colour with a cast of blueish brown j 
grows to a very large size, and perfectly repre- 
sents the head of some large fish abruptly cut 
off from the body. 
I must not omit obserying that the genus 
Diodon is that which misled Linneeus into the 
idea that the Cartilaginous fishes were furnished 
with a kind of lungs as well as with gills. In 
order to ascertain this point he requested Dr. 
Garden of Carolina to examine into the organs 
of the Porcupine and other Diodons in a living 
LFjCT- il 
