VI 



FISH GALLERY. 



The Dactylethrida {Xenopus, fig. 29) of tropical Africa and the 

 Pipidteof South America are small groups which form the suborder 

 of tongueless Frogs — the former being chiefly distinguished by the 

 presence of teeth in the upper jaw, whereas the latter are absolutely 

 toothless. The Surinam Toad (Pipa americana, fig. 30) is well 

 known for its curious mode of reproduction, the egs;s being placed 

 by the male in cells on the back of the female, where they remain 

 until the completion of the metamorphosis. 



Order II. CAUDATA, or TAILED BATRACHIANS. 



Elongate, lizard- or eel-like in form, with two, or, exceptionally, 

 one pair of limbs and with a tail. Short ribs are constantly present, 

 and the vertebral centra are biconcave or proccelous. Over 100 

 species are known, from Europe, Temperate Asia, North Africa, and 

 North and Central America, but they are entirely absent in the 

 Southern Hemisphere. They are arranged in four families : — 



1 . Snlamandridce. 2. Amphiumidce. 3. Pi'oieidce. 4. Si- 

 renida. 



Fig. 31. 



Ambhjdoina tiyriiuun (Axolotl of Mexico). 



The Salamandrida, or Newts and Salamanders, lose their gills 

 before they reach the adult state. However, there are instances 

 occurring in various genera, of which the Axolotl (fig. 31) is the 



