XX l] MAIN DIVISIONS 559 



little horny spines occur superficially in the epidermis. They only 

 enter the water at the breeding season and Toads are in many 

 respects more adapted to a land life than are Frogs. Two species 

 live in Great Britain ; Bufo vulgaris, found everywhere, and Itufo 

 calamita, the Natterjack, a species with comparatively feeble hind- 

 limbs, which crawls and does not jump. The Natterjack frequents 

 sandy places and is thus local in its distribution. 



The Bufonidae and several other families of Anura are stated 

 by septematists to have "dilated diapophyses." By this term is 

 meant broadened sacral ribs ; this broadening indicates a possibility 

 of back and forward play of the rib on the ilium, and points to a 

 use of the hind limbs in crawling as opposed to the purely leaping 

 movements of the frog. One species of Bufo (B. americana) is found 

 in the north of North America. But besides the Bufonidae another 

 family of the Arcifera, the Pelobatidae, which have teeth, is repre- 

 sented in North America by ScapMopus, a burrowing species and 

 on the continent of Europe by a closely allied genus Pelobates: both 

 genera are provided with a sharp spur on the inner side of each foot, 

 whence the name "Spadefoot" Toad which is bestowed on both. 



In another family the Discoglossidae the tongue is a round 

 cushion which is non-eversible. To this family belongs Alytes the 

 celebrated midwife toad. The male and female pair on land, the 

 male receives the egg- strings as they issue from the female, winds 

 them round his legs and keeps them there till the young hatch, 

 which they do in a much more advanced stage of development than 

 do the tadpoles of other toads. 



The Hylidae have teeth on the vomers and on the upper jaw, but 

 their most remarkable peculiarity consists in the possession of fleshy 

 cushions underneath the terminal joints of the digits, the bones of 

 which are bent up and claw-like. By means of these cushions the 

 Hylidae are able to adhere to smooth vertical surfaces, and so climb 

 trees, in which they mostly live, only approaching the water for the 

 purpose of laying their eggs. There is no species of this family in 

 Great Britain and only one in Europe. In North America there are 

 several species belonging to three genera ; Hyla, Chorophilus,a,ndAcris. 



The FIEMISTERNIA have the two epicoracoids fused in the 

 middle line and include the Frogs or Ranidae. TKere is only one 

 species, Rana temporaria, which is here taken as the type of the 

 Anura, really native to Great Britain, but there exist a few 

 colonies of the common European species, Rana esculenta, mostly 

 in the Eastern Counties. The Frogs of this species are most powerful 

 croakers, and as their name implies they are used as food. It is 



