25 



tail, attachment of the tongue, and development of the toes. 

 Specific differences will be found under their respective 

 headings. 



The larvae have external gills arranged in three tufts on 

 each side, with a long process in front of first gill, known 

 as the "balancer." The gills are upon the arches and 

 adapted for breathing air dissolved in water. There are no 

 internal gills, as in Anura. The larval heart consists of one 

 auricle and one ventricle, as in fishes, and is respiratory in 

 character, driving venous blood to the gills. In the adult, 

 true lungs are always present, and the heart has two auri- 

 cles and one ventricle. 



In development, the anterior limbs appear first and the 

 posterior follow.* 



Classification and List of our Local Species. 



The local fauna are embraced in the following classifica- 

 tion : 



Class, BATRACHIA. 



Order, URODELA. 



I I. Amblystomidce. 



-,-, ... II. Plethodontidce. 



Families \\ TTT _ 



111. Desmognai/iidcE. 



[IV. Pleurodelidce. 



Genera and Species. 

 Family I. ( Ambly stoma pnnctatnm. 



Vertebrae -< Ambly stoma op 

 amphicselous. ( Ambly stoma tig 



acum. 

 prinum. 



* The development of the anterior limbs of frog tadpoles is the same, but 

 they are concealed by the operculum until after the appearance of the hinder 

 limbs. This difference in the growth of the hood forms a distinguishing char- 

 acter by which the novice may determine the order to which a tadpole belongs. 



