112 RUDIMENTARY FORM OF THE 



\vith the posterior or inferior extremities of the 

 reptile, the bird, the quadruped, and man; upon 

 the same principle as even the claws of some kinds 

 of serpents, already alluded to, are received as ana- 

 logous to the arms, and the extremities of some 

 kinds of lizards are admitted as analogous to both 

 arms and legs. Fishes even rank before the ceta- 

 ceous tribes in this respect, since few of the latter 

 present any rudiments of posterior extremities at 

 all. 



In many fishes the ventrals are very much deve- 

 loped in length, but scarcely ever to the extent, 

 or to the same comparative breadth with the pec- 

 toral fins. They are long in the dories (Zeus.), 

 also in the genus Platax. In some other genera, 

 again, as Trichopus^ Osphromenus, and Calisa^ 

 they are longer than the fish, but consist of only 

 a single ray or filament. 



In some of the LopJiii anglers they have almost 

 the appearance of the paws of a quadruped, and in 



