INTKODUCTTON. 



This volume contains descriptions of, or references to, all the species 

 known at present of the Orders Caudata and Apoda. 



The latest general accounts of these animals are contained in 

 J. E. Gray's first edition of this Catalogue, published in 1850, and 

 in vol. ix. of Dumeril and Bibron's 'Erpetologie generale' (1854). 

 The numbers of species enumerated in these two works were 63 

 and 58 respectively, which must be greatly reduced when we 

 omit synonyms. 101 species are described in the present work, 

 four fifths of which are known to the author from autoptical exami- 

 nation *. The number of species in the British-Museum collection 

 amounts to 78, and that of specimens to 1021. The number of 

 species in the collection in 1850 was 38. 



The Apoda have been quite recently (1879) reinvestigated by 

 Professor Peters ; he enumerates 31 species, of which 17 were 

 known to him from direct examination. Dumeril and Bibron's 

 (vol. viii. 1842) and Gray's (1850) works contained descriptions of 

 8 and 9 species respectively. The present work contains diagnoses 

 of 32 species, 19 of which are represented in the national collection, 

 the number of specimens being 116. The collection contained only 

 5 species in 1850. 



* With the exception of five, the species of Tailed Batrachians not examined 

 by the author have been described by American Herpetologists. 



