FROGS AND TOADS. 



443 



Fig. 8. POUCHED FROG (Nototreina.) 



porarily bo the wateT they pass their whole time in trees or shrubs, 

 and are enabled to absorb the moisture from leaves by means of special 

 glands on the skin of the under surface of 

 the body. Some of the species inhabiting 

 the hottest parts of Brazil construct basin- 

 shaped nests of mud in ponds for the 

 protection of the eggs, this task falling en- 

 tirely to the share of the female. As an 

 example of a non-arboreal species, the 

 North American grasshopper-frog (Acris 

 gryllus) may be mentioned. This species, 

 which is the sole member of its genus, and 

 is very closely allied to Hyla, spends its 

 time among * herbage in moist situations. 

 More remarkable are the pouched frogs 

 (Notokrema), with several species from 

 Central and Western Tropical America, and 

 one from Pernambuco. These frogs are 

 also closely allied to Hyla, but the females 

 have a large pouch in the skin of the back, 

 with its aperture near the hinder end of the 

 body. In this pouch the eggs to the 

 number of about fifteen are deposited by 

 the male, and there they develop into tad- 

 poles. The gills of the tadpoles are protected by a special bell-like organ : 

 and the young do not leave the chamber until they have assumed the 

 adult form. 



A small number of genera constitute a family distinguished from the 

 Hylidce by the much greater expansion of the extremities of the horizontal 



transverse processes 

 of the sacral verte- 

 bra, and also by the 

 simple terminations 

 of the end joint of the toes. The 

 genera have a small geographical 

 range, but the family occurs in North 

 America, Europe, the Oriental coun- 

 tries and Papua. In the country first 

 named it is represented by several 

 species of Scaphiopus, nearly allied to 

 which are the two Central and South 

 European species of Pelobates. The 

 members of both these groups are 

 burrowing frogs, with the hind-toes 

 largely webbed, and in their move- 



Fig. 9. MIDWIFE FROG (Alytes). ments they are somewhat inter- 



mediate between the true frogs and 



the toads. The eggs of the European forms are laid in long strings, which 

 are twined by the males round the stems of aquatic plants. Another 

 European species (Pelodytes putictatiis), together with the other genera of 

 the family, differs from the foregoing in the mode by which the rod forming 

 the hinder termination of the back-bone is articulated with the last vertebra. 



Family 



Pdobatidce. 



