282 BAIRD'S REVISION OF THE 



Gene. Ossification extending to hjoid apparatus, carpus and tarsus. Vertebra much 

 compressed, with high crests. Three apertures in the skin of the cheeks, behind the 

 eye, not communicating with the cavity of the mouth. Hind feet much flattened ; 

 first and fifth hind toes nearly rudimentary. 



Section 2. Sphenoidal teeth absent. Carpus and tarsus not ossified in the adults. 

 Subsection 1. Tongue entirely attached as in Ambystoma. 



Plethodon, Tsch. Sphenoidal teeth on two tangent plates attached to the 

 sphenoidal bone. Skin glandular, exuding a milky fluid. Tail cylindrical. Body 

 more slender than in Ambystoma. Eggs deposited in packets under damp stones. 



Sub-section 2. Tongue attached anteriorly, evertile as in the Raniformes. 



Desmognathus, Baird. Sphenoidal teeth in two narrow patches, attached to the 

 edges of the sphenoidal bone. Occipital condyles very peculiar in consisting of 

 short cylinders projecting from the ex-occipitals, with their axes parallel to that of 

 cranium, and their extremities forming a spherically convex articulating surface. 

 Crest of first cervical vertebra transverse, with a strong ligament passing from each 

 end, across the posterior corner of the cranium, to be inserted into the lower jaw. 

 These ligaments prevent the opening of the jaws beyond a very slight amount. Eggs 

 (in the second species) wrapped round the body of the female, who remains in a 

 damp spot until they are hatched. 



Hemidactylium, Tschudi. Toes, four on the hind feet. Sphenoidal teeth in two 

 broad short patches. Skin somewhat granular. Costal furrows more deeply 

 impressed than common, extending to dorsal line. Tail narrower at the base than 

 near the middle. 



Sub-section 3. Tongue entirely protractile, capable of considerable protrusion, 

 circular in shape, and supported on the tip of the constricted hyoid apparatus. 



Oedipus, {Tschudi.) Body stouter than in Plethodon glutinosus. Sphenoidal teeth 

 on two plates, not in contact ; diverging behind. Toes dilated at the tips into sucker 

 like disks as in Hyla. 



PsEUDOTRiTON, Tsch Sphenoidal teeth much the same as in Oedipus, and the 

 other genera of this sub-section. Body very stout, less so than in Ambystoma 

 punctata. Tail equal to or less than the body. Breadth of scull about equal to the 

 length. 



