108 



BRANCH VERTEBRATA. 



FIG. 185. 



The Tiger Salamander (sal a man'der), found in the 

 warmer states east of the Rocky Mountains, is peculiar, 



in that it retains its 

 external gills so long 

 as it is kept in water ; 

 but on being allowed 

 to crawl on land, by 

 the drying up of the 

 pools, it soon loses 

 its gills, breathing by 



Amblt/sto'nia ti' grl num. Tiger Salamander, (f) ,, ! . 



means of lungs. As 



the Salamanders are without ribs, the air is forced into 

 the lungs by the animal's filling its mouth, closing its 

 nostrils, and then elevating its broad hyoid (hi' old) bone. 

 The common Newt, or Triton (tri'ton), is found in 

 nearly every slow running stream, and is often confined 



FIG. 186. 



Di e myc' t# lus vir i des' cens. Newt. ( |.) 



in the aquarium, making a most interesting pet. If an 

 adult be carefully examined, the scars left by the larval 

 gills can be found on the sides of its neck. 



ORDER ANURA (a nu'ra). 



This order includes those Batrachians which in their 

 growth have, as adults, not only lost their gills, but have 

 resorbed their tails. The Toads and Frogs are familiar 

 examples, and their metamorphoses have interested nat- 



