438 AMPHIBIA— ORDER I.—ECAUDATA. 



in water. One member of a Tropical American genus of this family— namely 

 Phyllohates trinitiUis, of Trinidad and Venezuela — is remarkable on account of 

 its curious nursing liabits. The tadpoles are provided with sucking-discs on 

 the mouth, by means of which they attach themselves to the back of their 

 female parent, and are thus carried about in safety. As many as from twelve 

 to eighteen tadpoles may sometimes be found thus clinging to one frog. A 

 similar mode of attachment occurs in one species of the under-mentioned 

 genus Dendrohates, but in this case this mode of locomotion seems to be 

 resorted to only when the ponds in which the individuals have bred dry up. 



In addition to the members of the genus Bhacophorus, there are many 



other frogs which have taken to an arboreal life, and so much do these 



resemble one another in external appearance that it is pro- 



Family bable any non-scientific observer would regard aU of them 



Dendrobalidce. as being very closely allied. Not so that dreadful personage 

 the anatomist, who tells us that while the members of one 

 family conform in the structure of the bones of the chest to the sub-order 

 now under consideration, all those of another family to be mentioned 

 later have a totally different conformation of this region. Accepting this 

 distmction, we must regard the Tropical American tree-frogs of the genus 

 Dendrohates, and those belonging to the nearly allied Malagasy genus Mantella, 

 as forming a family by themselves. From the frogs of the family Banida 

 the Dendrobatidw are distinguished by the absence of teeth both in the upper 

 jaw and on the bones of the palate. In both genera the toes are unwehbed, 

 and terminate in small adhesive discs, but whereas in Mantella the tongue is 

 notched at the tip, in Dendrohates it is entire. One species of the latter 

 genus (D. tinctorius) is remarkable for the brilliancy and variabUity of its 

 coloration ; while it is further noticeable as being less arboreal than its con- 

 geners, generally frequentmg low herbage or ground strewn with dead leaves. 

 As already mentioned, another species carries its tadpoles clinging to its back 

 from pool to pool in seasons of drought. 



Another nearly allied family of frogs is distinguished from the last by the 

 expansion of the extremities of the horizontal transverse processes of the 

 sacral vertebra ; both 

 Family groups agreeing in the 



Enrjystomatidce. absence of teeth in 

 the upper jaw. These 

 frogs present great variation in the 

 structure of the bones and cartilages 

 forming the chest ; the typical genus 

 Engystoma, together with Cacopus and 

 several others, showing the absence 



of the bones known as precoracoids — 

 a feature rare in the sub-order. This 

 family may be regarded as essentially 

 a southern one, its geographical range 



embracing Africa, Madagascar, the FUj. 3.— Cacojjws systema. 



Malayan Peninsula and Islands, India, 



the south of China, New Guinea, and South and Central America. Two 



species of the typical genus extend, however, into North America as tar as 



Mexico and Carolina. Nearly a score of genera are included in the family. 



Among tliese, a consideralilo iiuuiber are characterised by the extremely 



small relative width of the opening of the mouth ; and it is probable 



