2640 FROGS AND TOADS 



THE SOUTHERN FROGS 

 Family LEP TOD A c 



In the greater part of South America and almost the whole of Australia the 

 typical frogs are replaced by a family which, for want of a better name, we may 

 call the southern frogs. These, together with seven other families, differ essentially 

 from the forms hitherto considered, in regard to the conformation of the bones of 

 the chest, and thus collectively constitute a second suborder, known as the Arcifera. 

 It will be remembered that in the preceding suborder the two metacoracoid bones 

 are connected together by a single cartilage joining their free edges; in the present 

 group each metacoracoid terminates in a large cartilage, in such a manner that one 

 cartilage overlaps its fellow of the opposite side. The southern frogs resemble the 

 typical frogs in having the upper jaw alone toothed, and in the transverse processes 

 of the sacral vertebra being cylindrical or but slightly expanded, while they also 

 agree in the characteristics of the vertebrae and the absence of ribs. It is thus 

 evident that the two groups form parallel or representative series; but it must always 

 be remembered that it is only an assumption that the conformation of the bones of 

 the chest is the characteristic of primary import; and that it is quite possible that 

 there may have been parallelism in this case also, in which event the present 

 family would have to be placed next the true frogs. The present family is con- 

 fined to the countries mentioned above, and is represented by twenty-five genera 

 and some one hundred and eighty species. While most of the American forms 

 have the pupil of the eye horizontal, this condition occurs but rarely in those from 

 Australia. 



Among the best-known representatives of the family are the horned 

 Horned Frogs ^^ OT horned toads ( Ceratophrys) remarkable alike for their large 

 size and brilliant coloration, as well as for the enormous dimensions of their mouths 

 and their fierce and carnivorous habits. Represented by about half a score of spe- 

 cies from tropical and South America, they belong to a group characterized by the 

 more or less marked union of the outer metatarsals, the absence of a bony style to 

 the' breastbone, and the webbing of the hind-toes; while, as a genus, they are dis- 

 tinguished by the horizontal position of the pupil and the notching of the tongue. 

 The webbing of the toes varies in extent in the different species, but there is never 

 any expansion of these extremities. The outer metatarsals are completely united, 

 and the skull is remarkable for the extent to which ossification is carried out. In 

 some species, such as the Brazilian horned frog (C. boiet), the upper eyelid is pro- 

 duced into a horn-like appendage; but in others, like the Argentine horned frog (C. 

 ornata), this is little developed and scarcely noticeable. 



The largest representative of the genus is the above-mentioned Brazilian 

 horned frog, which attains as much as eight inches in length, and is one of the 

 most handsomely ornamented of the genus. The smaller Argentine species rep- 

 resented in our illustration differs from it by the upper eyelid being only slightly 

 pointed and triangular, as well as by the presence of a bony shield on the back. 



