THE GEOGRAPHICAL DISTRIBUTION 



OF THE 



BATRACHIA. 



Op the various primary Geographical Divisions which have been 

 proposed, that recognized by Giinther for Freshwater Fishes, into 

 Northern. Equatorial, and Southern zones, agrees best with the facts 

 deducible from a study of Batrachians. We have, however, to make 

 one modification, as for Batrachians a separate Southern zone does 

 not exist. Tasmania and Patagonia do not differ in any point 

 regarding their Frog-fauna from Australia and South America re- 

 spectively. In other words, the geographical distribution of the 

 Batracbia agrees in general with that of Freshwater Fishes ; whilst 

 other groups of cold-blooded Vertebrata, the Lacertilia for instance, 

 were subject to a totally different plan of dispersion, which is better 

 expressed by the divisions proposed by Sclater. 



In spite of the objections that have been made to the practice of 

 specialists to define geographical regions from considerations derived 

 from their own particular study, I still believe this to be the only 

 successful way of dealing with the subject ; and I consider that 

 fallacious conclusions would be arrived at if a division of the Globe's 

 surface made for Reptilia were applied, without modification, to 

 Bactrachians, or even to the several orders of the former Class. 



The following are the principal divisions adopted : — 



I. The Northern Zone. — Characterized by abundance of Caudata 

 and absence of Apocla. 



1. Europo- Asiatic or Palatarctic Region. — Numerous Salaman- 



drinw. Absence of Hylidai with a single exception. Dis- 

 coglossidce. 



2. North- American Region. — Sirenidai ; few Salamandrince ; 



Plethodontinoe, Amblystomatincp, and ffylidce numerous ; 

 Desmognath ince. 



II. The Equatorial Southern Zone. — Characterized by Apoda or 



absence of Caudata. 



A. Firmisternia Division (= Cyprinoid Division of Giinther). — 



Firmisternia greatly predominate (260 species out of 300). 

 Absence of Hylidos and CystignatJiidm. 



1. Indian Region. — No Aglossa or Dendrobatidos. 



2. African Region. — Dactyleihridoe or Dendrobatidce. 



B. Arcifera Division ( = Acyprinoid Division of Giinther). — 



Arcifera greatly predominate (370 out of 420). Hylidoz, 

 Cystignathida?. 



1. Tropical American Region. — Apoda, Pipida?, Hemiphractidai, 



Amphignathodontido}, Dendrophryniscidcp., Dendrobatidce. 

 Bufo numerous. 



2. Australian Region. — Absence of Apoda and Bufo. 



I 



