lieijtiles and Amphibkois of Illinois. 358 



SYNOPSIS OF THE FAMILIES REPRESENTED IN ILLINOIS. 



1 ( 2). Branchial tufts persistent. Vertebra? araphicoeli- 

 an 11. 



2(1). Branchial tufts lacking in adults 3. 



3(4). Vertebrae amphicoelian 7. 



4(3). Vertebrae opisthocoelian 5. 



5(6). Tongue small, and free only at the sides. Palatine 

 teeth in two longitudinal series. No parasphe- 

 noid teeth. Occipital condyles sessile. 



Pleurodelid^. 



0(5.) Tongue rather large, free laterally and posteriorly. 

 Palatine teeth in transverse series. Two para- 

 sphenoid patches of teeth. Occipital condyles 

 with pedicels Desmognathid^. 



7 ( 8). Tongue attached by a pedicel and all its margin 

 free, or by a narrow median strip, and free later- 

 ally and posteriorly. Palatine teeth transverse. 

 Parasphenoid teeth present. Carpus and tarsus 

 cartilaginous. Pterygoids wanting. 



Plethodontid^. 



8(7). Tongue largely attached, free in front and at the 

 sides 9. 



9 (10). Branchial apertures closed in adults. Palatine 

 series of teeth nearly or quite transverse, on the 

 posterior margin of the palatine bones. No 

 parasphenoid teeth. Carpus and tarsus ossified. 

 Pterygoids present Amblystomidje. 



10 ( 9). Branchial apertures open (in our species) or closed. 



Palatine series of teeth not transverse, on the 

 anterior margin of the palatine bones. Carpus 

 and tarsus cartilaginous Menopomid^. 



11 (12). With two pairs of legs. Jaws provided with teeth. 



Teeth on the roof of the mouth in an arched 

 series Proteid^. 



