586 AMPHIBIA. 



CLASSIFICATION OF AMPHIBIA. 

 Order ANURA or ECAUDATA. 



The adults have no tail or external gills or open gill-clefts. There 

 are always four limbs. 



Sub-order Phaneroglossa. Tongue present; the eustachian tubes 



open separately into the pharynx. 



Series A. Arcifera (see p. 564), e.g. the toothless toads (Bnfo) ; 

 the tree-frogs (Hyla), with adhesive glandular discs 

 on the ends of the digits ; the obstetric frog (Alytes) ; 

 Bombinator, Pelobates, and others. 



Series B. Firmisternia (see p. 564), the frogs proper (Ranidre), 

 e.g. the grass-frog (R. tetnporaria), the edible 

 frog (R. esculenta], the N. American bull-frog 

 (R. catesbiana), sometimes 8 in. in length, and 

 with a sonorous croak. 



Sub-order Aglossa. Tongueless ; the eustachian tubes have a 

 common median aperture into the pharynx. The Surinam 

 toad (Pipa ainericana\ and the allied African genus 

 Xenopus. 



Order URODELA or CAUDATA. 



The tail persists in adult life ; the larval gills and gill-slits may also 

 persist ; the limbs are weak when compared with those of Anura, and 

 the hind pair may be absent. 



Family i. Amphiumidse. The N. American Ajnphhnna, with two 

 pairs of rudimentary legs, with a slit persisting in 

 adult life as a remnant of the gilled state ; Crypto- 

 branchns inaxiinus^ the largest living Amphibian, 

 found in Japan and Thibet, attains a length of over 

 3ft. 



Family 2. Salamandridae. Salamandra maculosa and S. atra, both 

 European, both viviparous ; the usually oviparous 

 newts Triton or Molgevi which Triton alpestris 

 becomes sexually mature while still larval (p&dogenesis). 

 Desmognathus fusca, the common Inngless water 

 salamander of the United States, lays its eggs in a 

 wreath which the female twines round its body. The 

 N. American A/nb/ystowa, with its sometimes persistent 

 larval form the Axolotl, formerly thought to be an 

 adult of a different species (Sircdon pisciformis}. 



Family 3. Proteidce. Proteus and Neditrns, both with persistent 

 gills. Several species of Proteus inhabit the water in 

 the caves of Carinthia and Dalmatia in Austria. The 

 gills persist ; there are two pairs of limbs. The eyes are 

 degenerate ; the colours are pale, as we should expect 

 in cave-animals. Two species of Nectiirus (or Meno- 

 branchus] occur in N. America, in rivers and lakes. 



