328 



LOWER VERTEBRATES. 



They undergo their metamorphoses while of smaller size than most of the native 

 Anura. When they leave the water, they make long journeys in every direction, 

 hiding themselves during the day. Should rain fall, they emerge from their hiding- 

 places, and appear at times in great numbers, thus giving rise to the supposition that 

 they have fallen with the rain. 



A very small species of toad, JBufo quercicus, is found in the south-eastern part of 

 the United States from North Carolina to Florida inclusive. The largest North 

 American Hufo is the B. horeas of the Pacific fauna, which is sometimes nearly as 

 large as the B. marinus. A small species of the upper Missouri region (Bufo dipter- 

 nus) has two well-developed tarsal shovel-spurs, like some species of the South Amer- 

 ican genus Paludicola. 



There is a greater range of ossification of the skull in BufonidsB than in any other 

 family of Anura. Thus in the Australian Chelydobatrachus there is not only a 



Fig. 196. — Bombinator igneus, Unke, Feuerkrote. 



frontoparietal fontanelle, but the ethmoid bone is unossified above. (See page 320, 

 BufonidsB, Fig. 1.) In the Australian Pseudophryne and the European Epidalea, 

 the ethmoid is complete, but the fronto-parietal fontanelle remains. Epidalea calamita 

 is the natterjack toad of the English, and is confined to western Europe. In Bitfo 

 the skull is completely ossified, but the epidermis of the skull and often the derm, 

 are free. In the next stage the ossification involves even the epidermis (pi. cit. Bufon- 

 idse. Fig. 6), and over-arches the temporal fossa and muscle. This is the character of 

 the genus Beltaphryne, of which P peltacephala of Cuba is the type. The genus 

 Cranopsis of Central America has the same character, with the addition of imperfect 

 auditory organs. The typical species, C. fastidiosus is found in the high Cordillera 



