[ 281 ] 



ART. XXIII. — Revision of the North American Tailed-Batrachia, with descriptions 

 of nero genera and species. By Spencer F. Baird, Carlisle, Pennsylvania. 



The following notes, introductory to a more detailed memoir on the same subject, 

 will, it is hoped, throw some light upon this obscure portion of American zoology. 

 To this we would refer for the descriptions of species, with their anatomical and 

 physiological characters, giving only in this place brief outlines of the genera and 

 the synonymy of the species. It is probable that reference to some, hitherto 

 inaccessible, records will change the specific nomenclature to a certain extent; 

 this, however, can affect only a few. No synonyms or references are quoted, but 

 such as are based (as far as known) upon original descriptions, mere quotations from 

 the previous descriptions of others being omitted. 



BATRACHIA URODELA, Dum.' 



GROUP I. ATEETODERA, Dum. et Bib. 

 Branchial apertures obliterated at maturity. 



Section 1. Sphenoidal teeth absent. Carpus and tarsus ossified in the adults. 



Ajibystoma, Tsch. Vomerine teeth in an undulating transverse row, composed 

 of several curves varying with the species. Tongue broad, fleshy, filling interspace 

 of rami ; entirely attached except at the lateral and anterior edges, where it is slightly 

 free. Carpus, tarsus, and basi hyal ossified in extreme adults. Body very stout and 

 clumsy. Skin in some species, with close set glands, secreting a milky fluid. 



a. Tail sub-round. Toes rather long and slender, cylindrical or conical. 



js. Tail compressed. Toes short, broad, sub-palmate. 



NoTOPTHALMUS, Raf Tongue rudimentary; the end of the hyoid apparatus 

 appearing in the mouth as a simple knob. Vomerine teeth forming an acute V in 

 the palate ; the vertex between the posterior nares, the branches much prolonged 

 backwards. A bony orbit above the eye, formed by the union of processes from the 

 frontal and tympanic bones, enclosing a foramen through which pass flexor muscles 

 of jaw. Similar in this respect to Cijnops, Tsch., Pkurodeks, Waltl., and Euproctus, 



