38 FISH GALLERY. 



certain is that the disk-like dilatations of the tips of the fingers act 

 as adhesive organs (fig. 26), by means of which the animal attaches 

 itself to vertical or smooth surfaces, as may be observed in the 

 common Tree-Frog from the continent, which is frequently kept 

 in captivity in this country. 



Fig. 26. 



Foot of Hylambates pulmatus. 



The Dendrobatida are small Tree-Frogs, closely allied to the 

 preceding family, but destitute of teeth, in which respect they 

 resemble the Toads. The savage tribes of some parts of South 

 America extract a deadly poison for their arrows from Dendrobates 

 tinctorius, of which a specimen is exhibited, and from other allied 

 species. 



The Cystignathida represent the Ranidce in tropical America 

 and Australia. They differ from the true Frogs in the structure 

 of the sternal apparatus, which, as in Toads, belongs to the 

 " Arciferous ,; type. Several of the genera lack altogether a web 

 between the toes [Leptodactylus) , whereas others (e. g. Pseudis) 

 have the toes extensively webbed. This Pseudis Frog was believed 

 by the earliest observers who studied the fauna of the Guianas to 

 reverse the course of the ordinary metamorphosis and to change 

 into a fish. This fable originated in the enormous size of the 

 tadpole, which frequently far exceeds that of the perfect animal. 

 Several larvae of this interesting Batrachian are exhibited. The 

 Ceratophrys, or Horned Frogs, also belong to this family. 



The Bufonidce, or true Toads, have no teeth, and the transverse 

 processes of the sacral vertebra are more or less strongly dilated 

 or mallet-shaped. Two species, Bufo vulgaris (the Common Toad) 

 and Bufo calamita (the Natterjack), represent this group in the 



