Moodie — Distribution of the Fossil Amphibia. 187 



During the Triassic the Amphibia, as represented by the 

 Stereospondylia, attained their widest distribution in pre-Pleisto- 

 eene times, when they are known from all continents of the 

 globe excepting South America, even occurring as far north as 

 Spitzbergen and as far south as Cape Colony and Australia. 

 The group then went utterly out of existence from some cause 

 which it is impossible for us to ascertain, unless it be due to 

 some weakening of constitution owing to extreme specialization. 



The abrupt appearance of the frogs in the Jurassic of Spain 

 and England and in the Comanchean of North America is a 

 matter of great interest and would seem to indicate a long 

 antecedent history. The history of the modern Salientia and 

 Caudata is recorded in an almost unbroken series of discoveries 

 in Europe, but, so far as I have been able to ascertain, the 

 groups are not definitely known from North America until the 

 Pleistocene. It is quite possible that during the late Pliocene 

 or early Pleistocene forms migrated from North America to 

 South America, where, in the Pleistocene caves of Brazil, we 

 find the first traces of South American Amphibia in the genus 

 Leptodaetylus, which, as far as we know, is characteristic of 

 that continent. 



The Apoda are wholly unknown in geologic history, and we 

 now know them widely distributed as indicated by the accom- 

 panying "Table of Geologic and Geographic Distribution of 

 Amphibia." 



The information we have of the Amphibia is very incom- 

 plete and an attempt has been made to record the information 

 we have in as compact a form as possible. The distribution 

 of the Amphibia, as indicated by the remains which have been 

 recovered, is very puzzling, in that in Europe, Asia and South 

 America occur forms of Salientia which are so characteristic 

 of the various continents. In Asia in the Eocene occurs a 

 representative of the genus Oxyglossus, and the genus is still 

 represented in the Oriental region by three species of the same 

 and closely allied genera. South America is remarkable in 

 being the home of the genus Leptodactylus, which reached that 

 continent in Pleistocene times, and is now found in Australia 

 and the. whole of Central and South America. Europe has 

 the same kind of distribution as indicated by the salientian 

 family Paleobatrachidas from the Miocene, which according to 

 "Wolterstorff* is allied, on the one hand to the Pelobatidas and 

 on the other to the Xenopodidae, the former of which families 

 is now largely restricted to the Oriental region while the latter 

 is typical of the Ethiopian realm. The solution of this distri- 

 bution would seem to lie in that the various forms had, in the 



* Jahrb. nat. Ver. Magdeburg for 1886, p. 156. 



