NATURAL SCIENCES OP PHILADELPHIA. 99 



Batrachoseps pacificus Cope. 



Hemidactylium pacificum Cope, Proceed. Acad. Nat. Sciences, Phila. 1865, p. 

 195. 



HEMIDACTYLIUM Tschudi. 



Classif. der Batrachier Trans. Neuchatel, 1838, p. 54 — 94. Bonap., Fauna 

 Ital. ii, 131, No. 10. Fitzinger, Syst. Rept. 33. Baird, Journ. Ac. Nat. Sci. 

 Phila. i, 284, 1849. Hallowell, 1. c. 1858, 3(55. Gray, Cat. Brit. Mus. 1850, 41. 

 Desmodactylus Dum, Bibr. Erp. Gen. 8 p. 



Tongue adherent anteriorly. Digits 4 — 4. Parietal bones fully ossified, 

 without fontanelle? Two premaxillaries, with fontanelle. 



This genus is only distinguished from Plethodon by the deficiency of its hind 

 foot in digits. Those that remain are quite rudimental. There is but one 

 species known, and its habits are entirely terrestrial. 



Hemidactylium scutatum Schlegel. 



Salamandra scutata iich.\Qg%\,},i\xs.'L^jCi. Abbildungen, t. 40, f. 4, 6, 1837. 

 Fauna Japonica, ii, 119. Hemidactylium scutatum Tschudi 1. c, Bonaparte 1. c, 

 Baird, Hallowell, Gray 1. c. Salamaiidra melanosticta Gibbes, Bost. Journ. Nat. 

 Hist. V, 89, t. 10. Desmodactylus melanostictus Dum., Bibr., viii. Salamandra 

 fusca Green, Journ. A. N. Sci. Phil, i, 337, 1818, not S.fusca Raf. 



PLETHODON Tschudi. 



System d. Batrachier Trans. Neuchatel, 1838, 59 — 92. Bonap., Fauna Italica, 

 ii, 131. Baird, Journ. Ac. N. Sci. Phil, i, 292. Hallowell, ib. 1858, 342. Cope, 

 Proc. A. N. Sci. Phil. 1859, 124. 



Tongue attached by the median line below, from the glossohyal bone to 

 near the anterior margin ; pterygoid teeth in two patches, more or less ap- 

 proximated ; a large fontanelle between the spines of the separate premaxillary 

 bones. Toes 4 — 5, normal. Anterior teeth not enlarged. Cranium well ossi- 

 fied. Two premaxillary bones, their spines embracing a fontanelle. 



This genus is highly characteristic of the Regio Nearctica, where three 

 species represent it on the Pacific slope, and two in the Eastern district. A 

 species from Japan, named P. p e r s i m i 1 i s by Gray, is shown by Mivart not 

 to belong to this genus.* The species are all terrestrial in their habits, and 

 three which I have observed (P. oregonensis, P. glutinosus, P. ery- 

 thronotus) undergo their metamorphosis while quite small. The last 

 named, and probably P. glutinosus, never enter the water, but are hatched 

 in damp places on land. The branchias have therefore no functional service. 



St. The pterygoid patches in contact throughout ; vomerine series well 

 separated medially. 

 Costal plicas 16 to 19 ; form slender, tail cylindric, limbs weak, inner toes 

 rudimental ; vomerine series not extending beyond nares externally ; belly 

 brown marbled ; above plumbeous or with a red longitudinal band. 



P. erythronotus. 



Costal plicae 13 ; form slender, tail well compressed ; limbs weak, inner toes 



rudimental ; vomerine series not extending outside of nares ; belly brown 



marbled ; above with a red dorsal band P. intermedins. 



Costal plicae 14 ; form stout, tail rounded ; limbs short, stout ; inner digits 

 distinct ; vomerine series extending outside of inner nares ; black, usually with 

 gray lateral blotches and smaller dorsal spots P. glutinosus. 



A:t. The pterygoid patches well separated, vomerine series closely approxi- 

 mated medially. 



* Mivart calls it Pectoglossa, but gives no character by which it can be separated from 

 Amblystoma. 



1869.] 



