446 AMPHIBIA— ORDER II.—CAUDATA: 



three species altogether. Of these, one is an axolotl from Siam, belonging 

 to the American genus Amhlystuma, while the other two constitute the genus 

 Tylotritoii, one inhabiting the Liu Kiu Islands, and the other the eastern 

 part of the Himalaya and Yunnan. All the tailed amphibians are nocturnal 

 creatures, the great majority of which pass some portion of their time in 

 water, while others are permanently aquatic. Such as develop lungs and 

 lose their gills have to rise periodically to the surface of the water in order 

 to breathe. Their tenacity of life forms a striking feature in the physiology 

 of these creatures ; species inhabiting tropical regions, subject to periodical 

 droughts, becoming torpid at such seasons, while those from colder regions 

 hibernate. Even envelopment in ice is not alw ays sufficient to destroy life. 

 The same low organisation is indicated by their power of reproducing the 

 tail and limbs. Whereas the majority of species have large and well-develcped 

 eyes, a few which inhabit underground waters have lost the power of 

 sight, and have the rudimental eyes deeply buried beneath the skin. The 

 aquatic species swim chiefly or entirely by means of a tail, and thus differ 

 markedly from the frogs, in which the hind-limbs alone are employed. Most 

 of the terrestrial forms are slow-moving creatures, although a few dart about 

 with the rapidity of lizards. Certain members of the order are peculiar in 

 producing living young, the tadpoles being in some cases retained within the 

 body of the female until considerably developed. 



The greater number of the members of the order are included in the 



family typified by the common yellow and black salamander, although the 



genera may be arranged in four sub-families. As a family, 



Family the Salamandyidce are distinguished by undergoing a full 



Salamandridce. metamorphosis, with the consequent loss of the gills in 



the adult condition, as well as by the presence of teeth in 



both jaws, of eyelids, and of maxillary bones. In the typical sub-famDy 



Salamandrina', the teeth on the palate are arranged in the foim of a pair of 



posteriorly diverging rows, such rows being situated on the inner margins of 



two long processes running backwards from the j'alatine bones. Ko teeth 



are deyeloped on the bone forming the hinder pnit of the inner surface of the 



slvitll, and known as the parasphenoid ; 

 and in the backbone the bodies of the 

 vertebrfe have a cup at the hinder end, 

 and a ball in front. The common black 

 and yellow salamander {Salamandra 

 nmcxdiina) is the best-known representa- 

 tive of the typical genus of the sub- 

 family, which includes two other species, 

 and is confined to Central and Southern 

 Europe, Algeria, and Syria. From the 

 newts, the typical salamanders may he 

 distinguished by the following features. 

 Fig. ii.-CoMMON SALAMA^;^(5a!a. In f"r™ the tail is cylindrical and taper- 

 mandra macuiosa). nig ; there are five toes to each ot tne 



hind-feet ; the two rows of the teeth on 

 the palate are curved ; and the tongue, wliich is of rather large size, and 

 nearly oval in form, is free at the sides, and to a certain extent behind. The 

 black ground-colour, marked with a double row of longitudinal yellow 

 blotches on the head and back, and similar markings on the upper surface of 

 the tail and limbs, sufficiently distinguish the salamander from the other 



