HELL-BE NDEE 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 SALAMANDRID^. THE SALAMANDERS. 



Gradientia, Oppel, Gray. 

 Psmdo-sauriena, DbBlainville. 

 Atretoderes, Dumeril and Bibkon. 

 Myctodera of some authors 



Gill-slits perfectly oloaed 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 usnajly large ; dentaries and premaxillsa 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 Atretoderes, ftom Atratoa, without a foramen, 

 and Deras neck, with Trematoderei, which they applied to the remainder of the Urodela. 

 The latter name etymologicaliy considered seems to be a good one, but unnecessary, as 

 is also its synonym, Immutabilia of Fitzinger. 



*Vomero-palatine teeth in two longitudinal rows divergent behind, or sphenoidals 

 present in two elongated groups, and thus divergent, a. 



*Vomero-palatine teeth transversely arranged, or wanting, or convergent posteriorly. 



Ambltstoma. 

 a. Hind toes four on each foot. 6. 



a. Hind toes five. u. 

 6. Tongue attached in front by a membrane. . . . Hemidactylium. 

 6. Tongue free all around, boletoid ; extralimital. . . Batrachoseps. 

 c. Sphenoidal teeth in two longitudinal groups of several rows each; vomero- 



palatines in a transverse series, d. 

 0. Sphenoidal teeth wanting ; vomero-palatines in two longitudinal rows, never 



in a transverse series. Notophthalmus, 



d. Tongue attached in frout by a membrane, e 



d. Tongne free all around, boletoid^ Spelerpes. 



e Vomero-palatine teeth in a continuous transverse row ; commissure much 



curved ; extralimital Akaides. 



e. Vomero-palatine series more or less interrupted medially ; commissure 



nearly straight Plethodon. 



Qenub AMBLYSTOMA. Tschudi. 



jPlagiodon, Dumeril and Bibron, includes Xiphonura, Tschudi, and Seterotriton, Gray. 

 Palatine teeth in a transverse, often interrupted row, sometimes in the form of an arch or 



