NORTH AMERICAN BATRACHIA AND REPTILIA. 
7 
present or absent Menopomidce. 
B. Teeth on posterior or inner margin of palatines; no 
anterior axial bone; gill-clefts closed in completely developed 
specimens. 
a. Yertebree amphicoelian; parietals embracing frontals; 
palatines with teeth on their posterior portion, not pro- 
longed over parasphenoid ; occipital condyles sessile. 
x. Carpus and tarsus osseous; parasphenoid without 
dentigerous plates ; pterygoids present ; pre- 
frontals prolonged and embracing frontals. 
AmbLystomidce. 
y. Carpus and tarsus cartilaginous ; parasphenoid 
with dentigerous plates; pterygoids wanting; 
prefrontals not prolonged or embracing frontals. 
Plethodontidce. 
b. Vertebrae opisthocoelian; parietals not embracing frontals. 
x. Carpus and tarsus cartilaginous; palatines with 
teeth on their posterior portion, not prolonged 
over the dentigerous parasphenoid; pterygoids 
and prefrontals wanting; occipital condyles ped- 
icellate Desmognathidce. 
y. Carpus and tarsus osseous; palatines with teeth on 
the inner margin of the separate processes which 
extend backward over the n on-dentigerous par- 
asphenoid; pterygoids and prefrontals present; 
occipital condyles sessile Pleurodelidce. 
Artificial Synopsis of Families. 
A. An opening on side of neck. 
a. Limbs small; toes 2-2 or 3-3 Amphiumidce. 
b. Limbs well developed; toes 4-5 Menopomidce. 
B. No opening on side of neck when completely developed. 
a. No patches of teeth (parasphenoid) on middle of roof of 
mouth behind; one or more series (palatine), usually 
transversely arranged, in front AmbLystomidce. 
b. Patches of teeth (parasphenoid) on middle of mouth 
behind. Without a row of large red spots on the sides. 
x. Characters not combined as in the following. 
Plethodontidce. 
y. Anterior margin of tongue attached; toes 4-5; 
costal folds not Over 15; tail compressed and 
finned above and no dorsal band, or parasphe- 
noid patches of teeth well separated and a yel- 
lowish dorsal band Desmognathidce 
