CHAPTER VI 



LISSAMPHIBIA {CONTINUED) ANURA 



Order III. ANURA or TAILLESS AMPHIBIA. 



The recent tailless Amphibia, or Frogs and Toads in the widest 

 sense, contain such a great number of species (about 900), with 

 such a diversity of characters, that it is necessary, if only for the 

 sake of mere convenience, to group them into a considerable 

 number of families and sub-families. The characters available 

 for this purpose are few. 



1. The possession of a toiigue cliaracterises the Phaneroglossa, the absence 



of a tongne the Aglos.sa. 



2. The character of the shoulder-girdle. — ^Overlapping of the two 



halves of the shoulder -girdle on the ventral side characterises the 

 Arcifera, while in the Firmisterxia the two ventral halves meet in 

 the middle line and form a firm, median bai-. See, for details, j). -2 A. 



3. The shape of the transverse processes or diapophyses of the .sacral 



vertebra which carries the iliac or hip-bones. These processes are either 

 dilated or cylindrical. 



A. The presence or absence of teeth in the upper and lower jaws. This is 

 indicated by a formula in which means absence of teeth ; max. means 

 presence of teeth in the U2>2)er jaw ; maud, means presence of teeth in the 

 lower jaw. 



5. The terminal joints or phalanges of tin- fingers and toes are sona- 



times claw-shaped. See p. 26. 



6. The shape of the centra of the vertebrae. — Opisthocoelonx, if the 



posterior end is cup-shaped or concave, procix'loiis if the anterior end is 

 concave and the posterior ia conve.x. See p. 19. 



By means of those characters we can arrange tlir .Vnura in 

 the following key : — 



