Boulenger gives the following synopsis:–
III. The series of palatal teeth converge backwards, forming a V-shaped figure.
With 5 toes: Hynobius, 3 species in Japan.
With 4 toes: Salamandrella, 2 species Lake Baikal, Ussuri and Schilka rivers, and Kamtchatka, p. [109].
III. The series of palatal teeth form an uninterrupted, doubly arched V-shaped figure.
The 4 fingers and 5 toes are furnished with black, horny claws: Onychodactylus japonicus.
III. The series of palatal teeth form two arches, convex forwards, separated by a wide interspace.
The two series are short, confined to the space between the choanae.
With 5 toes: Ranidens sibiricus, Eastern Siberia and N.E. China.
With 4 toes: Batrachyperus sinensis, Moupin in China.