230 



BRANCH CHORDATA 



it is spotted with small white specks. When swimming, the limbs are folded 

 back. 



The other species {Pseudobran'chus stria'tus) is only about 7 inches in 

 length and has three digits to each fore foot. 



p^'T At^TH 'A'\^'^ "i \ /f>/^si^j|^"^^ 



Fig. 188. — Mud-puppy. (Chapin and Kcttger, Englehard & Co., Pub- 

 lishers.) 



The family Prote'idce consists of amphibians having three pairs of per- 

 sistent gills, two pairs of weak limbs with four digits to each one, or the 



Fig. 189. — Pro'leus angtii'itiis. Europe. iFrom Dodge's " CI encral Zool- 

 ogy," American Book Co., Publishers.) 



aiiterior pair with two, and the posterior with three digits. The eyes are 

 without lids and covered b>- a transparent skin, but are functional. They 

 have teeth on the vomer, mandible, and preniaxillaries. 



