ZOOLOGY. 



615 



Number of Amphibians. 



The last enumeration of the Amphibians by Mr. Boulenger shows that 

 nearly a thousand species are known. Nine hundred and thirty -three 

 species "are described" in the catalogues of the Batrachia salientiaj 

 gradientia, and apoda of the British Museum. The progress of our ac- 

 quaintance since the commencement of the century with the Amphib- 

 ians, so far as numbers at least are concerned, may be seen from the 

 following tabular synopsis: 



Amphibians. 



Gynmopliidia 

 Gradientia... 

 Salientia 



Daudia. 

 1802-'3. 



D. &B. 



1842-'54. 



58t 

 164t 



B. M. 



1850-'58. 



9t 



63+ 

 2835 



Boul. 

 1882. 



33 

 101 



800 



933 



*Dum6ril&Bibron, 1842. tDum6ril .feBibron, t. 9, 1854. :t Gray, 1850. §GUnther, 1858. 



The Apodal Amphibians. 



The known apodal Amphibians do not exhibit suflQcient diiferences 

 among themselves to necessitate subdivisions of more than generic im- 

 portance, and all have been retained in one family — the Coeciliids. Some, 

 however, have " cycloid imbricated scales imbedded in the skin," and 

 others are naked ; some again have " eyes distinct or concealed under 

 the skill,'- and in others the eyes are " below the cranial bones." Tenta- 

 cles are developed between the nostrils and eyes, or below them, and 

 their modifications of structure have afforded the means of definiug a 

 number of genera. Mr. Boulenger has admitted 11 genera, and recog- 

 nizes 32 species ; South America has 21 species, Africa 5, and India 5. 



Families of Urodele Amphibians. 



The families of Gradient or Urodele Amphibians admitted by Mr. 

 Boulenger are much more comprehensive than those generally adoj)ted 

 by naturalists in the United States, who have accepted those established 

 by Professor Cope. Only four are admitted, Salamaudridte (with four 

 subfamilies), Amphiumidte, Proteidse, and Sirenidse, and the charac- 

 ters employed to differentiate two of them at least appear to contrast 

 strangely with those which are subordinated to them; thus, the Sala- 

 mandrids and Ami)hiumids are only differentiated because the former 

 have "eyelids developed" and the latter "no eyelids." The relations 

 the Boulengerian families bear to the Copean may be seen from the fol- 

 lowing exhibit : 



I. Caducibranchiata Cope, = (Salamandridse -f Amphiumida^ B.) 

 Gradients with "no gills in the perfect state, maxiUaries present, both 

 jaws toothed". (B.) 



1 a. Salamandrids =SalamandTi(lsd Salamandrinse pt. B. Caduci« 



