Hurter — Herpetology of Missouri. 79 



not until the last of July that they assume the colors of 

 the adult. From the time when the eggs are laid until the 

 young have taken the complete adult form and color about 

 four and a half months elapse. The animal is then two 

 and a half inches long. 



Colonel Pike regards A. opacum as strictly terrestrial, 

 entering the water only for the purpose of depositing its 

 eggs. They will eat almost any animal substance that 

 they can swallow. The Colonel also states that this spe- 

 cies hibernates late, hiding under leaves and burrowing 

 in the ground. He says it has been known to burrow in 

 soft ground to the depth of three feet. (Hay.) 



Dates of capture. — Apr. 6, 16 ; May 3 ; Sept. 5 ; Oct. 24 ; 

 Nov. 13. 



Family Plethodontidae. 



No branchial tufts; openings closed in adults. With four legs, four 

 fingers, toes four or five. Palatine series of teeth more or less trans- 

 verse. Teeth on the raaxillaries and premaxillaries. Parasphenoid 

 teeth present. The tongue attached by a slender median pedicle and 

 free all around, or attached by a median strip which extends from 

 the anterior margin to about the middle, the tongue being thus free 

 at the sides and behind. Palatines not prolonged over the parasphe- 

 noid. Pterygoids wanting. Prefrontals present, not prolonged and 

 embracing frontals. Premaxillaries generally embracing a fontanel. 

 Occipital condyles sessile. Carpus and tarsus ciirtilaginous. Vertebrae 

 amphiccelian. Eye-lids present. (Garman.) 



Synopsis of Missouri Genera. 



Tongue attached by a median strip, and free at the sides and 

 behind. Two premaxillary bones. Fingers four. Toes four. 

 Parietals ossified. Hemidactylium. 



Fingers four. Toes five. Parietals ossified. Plethodon. 



Tongue attached by a pedicle and free all around. One premaxil- 

 lary bone, with a fontanel. Fingers four. Toes five, free. 

 Cranial bones ossified. Spelerpes. 



Genus hemidactylium. 



Fingers four, toes four. Tongue attached by a median strip, free 

 laterally and posteriorly. Palatine teeth interrupted medially. Para- 

 sphenoid patches not in contact. Parietals ossified, without fontanel. 

 (Garman.) 



