HELL-BENDER OR MUD-DEVIL. 717 
ing. The individuals observed by Grote all had an intermittent sway- 
ing motion in the aquaria during July and August, which he conjectured 
might be either connected with the animal’s effort to cast the skin or a 
movement to attract the opposite sex. The Menopoma oviposits in 
August and September, probably for this purpose visiting the muddy 
banks of rivers. The eggs are at first about the size of a pea, enveloped 
in a glairy albuminous fluid. They are connected in strings, and in- 
crease after oviposition by imbibition of water. The Hell-bender at the 
time of pairing, changes its appearance, the tail becoming broader and 
the folds upon the sides varying. 
FAMILY SALAMANDRIDA. THE SALAMANDERS. 
Gradientia, OPPEL, GRAY. 
Pseudo-sauriens, DEBLAINVILLE. 
Atretoderes, DUMERIL and BIBRON. 
Myctodera of some authors. 
Gill-slits perfectly closed in the adult state; skull broad; palatines present in the 
young, and arranged as in Trachystoma and Proteida, but change their relations with the 
growth of the animal; nasal bones usually large; dentaries and premaxille bearing 
teeth; limbs four, well developed ; anterior toes four; fourth finger with three 
phalanges ; eyelids two, an upper and a lower, very distinct. 
Dumreil and Bibron contrasted the term Atretvderes, from Atrates, without a foramen, 
and Deras neck, with Zrematoderes, which they applied to the remainder of the Urodela. 
The latter name etymologically considered seems to be a good one, but unnecessary, as 
is also its synonym, Immutabilia of Fitzinger. 
*Vomero-palatine teeth in two longitudina! rows divergent behind, or sphenoidals 
present in two elongated groups, and thus divergent. a. 
*Vomero-palatine’teeth transversely arranged, or wanting, or convergent posteriorly. 
AMBLYSTOMA. 
a. Hind toes four on each foot. 0. 
a. Hind toes five. ec, 
b. Tongue attached in front by a membrane. ; : » HEMIDACTYLIUM. 
b. Tongue free all around, boletoid ; extralimiial. 6 6 BATRACHOSEPS. 
¢. Sphenoidal teeth in two longitudinal groups of several rows each; vomero- 
palatines in a transverse series. d. 
c. Sphenoidal teeth wanting; vomero-palatines in two longitudinal rows, never 
in @ transverse series. 4 ; ; ; ; : NOTCPHTHALMUS. 
d. Tongue attached in front by a membrane. e 
d. Tongue free all around, boletoid. . ‘ : ; : . SPELERPES, 
é Vomero-palatine teeth in a continuous transverse row ; commissure much 
curved ; extralimital. : : ; . - ANAIDES, 
e. WVomero-palatine series more or less interrupted medially ; commissure 
nearly straight. : : . ; : . : . PLETHODON. — 
GENUS AMBLYSTOMA. Tschudi. 
Plagiodon, DuMERI and BIBRON, includes Xiphonura, Tscuupi, and Heterotriton, Gray. 
Palatine teeth in a transverse, often interrupted row, sometimes in the form of an arch or 
