308 



LOWER VERTEBRATES. 



94 



The Amphiushd^ are snake-like creatures which differ from the allied families in 

 some characters of the skull. There are two genera, Am2jhiuma and Jlicrcetiopsis, 

 the former with two, the latter with three toes on the rudiniental limbs. Both have a 



Fig. 175.— Siren lacertina, umd-eel. 



slit communicating with the pharyngeal cavity on each side. The Amphiiana means 

 occurs in the southeastern states of North America, while the JUiircenopsis triclactyla 

 ranges as far as the borders of Texas. These are the only species of the family. 

 They look very much alike, with their rather acute extremities and dark color. They 

 live in the bayous and muddy ditches of the flat coast countries. 



There are but two genera of the Peotonopsid^ ; Protonopsis, of North America, 

 and Megcdobatraclms, of Asia. These are salamander-like animals with four well-devel- 

 oped but short limbs. There are branchial slits in the American genus, but none in 

 the Asiatic form. There are but two species of Protonopsis, P. horrida and P.fus- 



