BATRACHIA. 327 



front and the cup behind, instead of the cup in front and tlio ball behind. Of these 

 two families, one, the Discoglossidaj, has short ribs, as in the salamanders, and has a 

 sternum formed of two diverging branches. In the other familj-, the Asterophrydidae, 

 there are no ribs, and the sternum is not divided. In the other two families the 

 habitus is very different, since the one, the Ilylidie, passes its life in the trees, and the 

 other, the Pelobatidae, consists mostly of burrowing subterranean species. In the for- 

 mer, the last or ungual phalanges have a ball-shaped base, from which projects from a 

 notch, a curved, sharp, claw-shaped termination. This suiiports an exi)ansioii of the 

 integuments of a disc-like form, which enables the animals to adhere to any suitable 

 more or less vertical surface. In the Pelobatidae the ungual phalanges are simple, as 

 in other families. The two remaining families have teeth in both jaws. In one of 

 these, the Amphignathodontidfe, the sacral transverse processes are dilated. There 

 is but one genus and species, which is of South American habitat. The sacral 

 orocesses are not dilated in the other family, the Hemiiihractidie, which is also a small 

 South American grou]i. 



The family of the toads, Bufonid^, is found in various re])resentatives all over the 

 world, but it reaches its greatest develojiment in the tropics. A few weakly forms 

 with imperfectly ossified skulls occur in Australia, and in Mexico occurs the genus 

 Rhinophrijnus, which is remarkable for the great compactness and strength of its 

 ossification. The li/tinophri/nus dorsalis, the only species, is of subterranean habits, 

 and its powers of excavating the earth are largely dependent on the large shovel 

 formed by the projecting horny-sheathed cuneiform bone of the hind foot. Of 

 ninety-two species of Bufonida?, the genus liufo includes seventy-seven. The 

 largest species is £. inarinus of tropical America, which not unfrequently is eight 

 inches in the length of the head and body. Some of the Sufones have the head 

 marked with bony ridges, and in the B. typhonius these are developed into elevated 

 crests, giving the animal an extraordinary appearance. Some species are furnished 

 with a shovel for digging, as in Rhwophrj/nus ; such is Ji. compactilis of Mexico. 

 The common species of the eastern United States is J}, lentiginosus, which has 

 several varieties. The typical form is found in the Gulf States. The two bony crests 

 which form the eyebrows terminate each in a rounded knob. In the form which is 

 found in the middle, northern, and western states, the sub-species americanus, these 

 knobs are wanting. A peculiar variety, JB.fowleri, occurs in Massachusetts and in the 

 Dominion of Canada. The crests in this form are thickened behind, and nearly or 

 quite join, forming an osseous boss on the skull. The voice and habits of this form 

 are said to be quite different from those of the B. americanus, which is found in the 

 same region. 



The common toad of the middle states is a well-known inhabitant of gardens and 

 other localities where insects abound. Its habits are crepuscular, and its quiet though 

 sudden movements in the evening are familiar to every dweller in the country. It is 

 one of the first of the Batrachia to enliven the spring with its note, as it rests in the 

 water during the process of depositing its spawn. Its voice is a sonorous urr-r-r-r-r-r, 

 and the pitch varies with the individual toad. It prolongs its singing period well 

 into the summer, and its music in retired ponds and swamps, as darkness creeps over 

 the face of nature, is both weird and somnific. The eggs are deposited in a single 

 line in the central tube of a long rope of a transparent albuminous substance, which 

 assumes a coiled shape on the bottom of the water where it is deposited. The tad- 

 poles retain their early black color, thus differing from those of most of our Anura. 



