I/O 



WILLIAM A. HILTON. 



5. All forms live away from the light much or all of the time, 

 two have lost the use of their eyes and numbers of the genus 

 Spelerpes live in caves to some degree. 



>^ 



FIG. 4. ' Hyo-branchial apparatus of full-grown larvae of Spelerpes bilineatus 

 from below, showing the single " Copulastiel." X 6. 



Judging from these similarities may not a series of forms be 

 named in which all the members are closely related to each other, 

 and which shows the different degrees of adaptation of one dis- 

 tinct line of Urodela ? 



FIG. 5. Hyo-branchial apparatus of Typhlomolge rathbnni from above, 



after Emerson. X 6. 



