THE liATRAClIIA OF NORTH AMERICA. 47 



able to establish." TLo latter geuus, together with Eauideiis, Oiiycho- 

 dactyhis and Salaniaudrella from Asia, have beeu since referred to the 

 Auiblystoiuidai by Bonlaugcr, but I now lind the hyold apparatus to be 

 quite ditfireut iu the two groups. 



Three genera of this family are known to me. Another has beoji 

 distinguished on dental characters (Dicamptodou), but whether iden- 

 tical with or distinct from those I have seen I do not yet know. 



I. Vomcropalatiue teetli in a transverse line, whicli is straight or augulated and not 



much interrupted at the middle. 

 Otoglossal cartilage forming a ring, attached jiosteriorly to the first basibran- 



chial cartilage Amhlystowa. 



Otoglossal cartilage formiug a subtriangular plate attached posteriorlj^ to (lie 



first basibranchial Chondrotun. 



II. Vomovopolatine teeth in two series, separated by a wide interspace. 



Otoglossal cartilage not annular, free from the basibranchial, on which it moves j 



tail round Ungncdapsiis. 



Tail compressed; dental series converging backward D'lcmnpiodon. 



The species of these genera are all North American excepting the 

 Amblystoma persimilis Gray of Siam. 



AMBLYSTOMA, Tschudi. 



Tschndi, Batr., p. 92 ; Baird, Journ. Ac. Phila.(2), i, 1850, p. 281; Gray, Cat., p. 34; 

 Dum. & Bibr. ix, p. 101 ; Cope, Proc. Ac. Phila., 1867, p. 16G; Strauch, Salam, p. 

 GO ; Boulenger, Cat. Batr. Grad. Brit. Mus., 2d ed., 1882, p. 3S. 

 Xiplioiinra, Tschudi, I. c, p. 95 ; Gray, I. c. ; Dum. & Bibr., p. 161. 

 Sulamandroiihs, Fitzing., Syst. Rept.,p. 33. 

 Hehrotriion, Gray, I. c, p. 33. 

 Camarataxis, Cope, Proc. Ac. Phila., 1859, p. 122. 

 PecloijloHsa, Mivart, Proc. Zool. Soc, 1867, p. 698. 



Lai val forms : 

 Siiedon, Wagl., Syst, Amph., 1830, p. 209 ; Dum. & Bibr., p. 176. 

 Axoloit's, Owen, Ann. and Mag., N. H., xiv. p. 23. 

 Desmiostoma, Sagcr, Penins. Jour. Medic, 1858, p. 428. 



Vomerine scries of teeth in the same line, though often interrupted. 



Quadratqjugal bone wanting. Premaxillary bones distant from each 

 other, not embracing a fontanelle. 



Tongue attichcd by its whole base, but with a narrow free margin on 

 all but the posterior portion, capable of but a moderate protrusion. 



The otoglossal cartilage forms a ring, which passes entirely round the 

 circumference of the interior base of the tongue. It sends a process 

 on each side near its base, which terminates above theceratohyals with- 

 out articulating with them. 



Hypohyal cartilages slender, of moderate length. (Plate 20.) 



Ceratohyal articulating by its abruptly recurved superior extremity 

 with the posterior distal part of the quadrate. (Plate 48, figs. 8-10.) 



Digits 4-5, free, not connected by natatory membrane. 



A stratum of crypts more or less thickened on the parotoid region 

 and along the superior lateral region of the tail. 



A series of mucous pores round the orbit and for some distance ante- 

 rior to it. 



