BRANCHIFERA. AXOLOTLS. 75 



humor. This humor appears to be poisonous to feeble animals; 

 but the Salamander is not, as is supposed among certain country 

 people, an injurious animal. 



19. There has been discovered in America, a large batrachian, 

 of the precise form of the Salamander, that has an orifice on each 

 side of the neck, but which, it is supposed, never has branchiae. It 

 is probable, however,that these organs do exist in the first periods 

 of life, but disappear at an early date, as is the case in the terres- 

 trial Salamander. These reptiles, which form the genus MENOPOMA, 

 inhabit the great lakes and rivers in the interior of South America, 

 The AMPHIUMA, which inhabit the same continent, possess the 

 same mode of organization ; but their body is excessively elon- 

 gated, and their extremities are but little developed. The number 

 of their toes varies from two to three, according to the species. 



FAMILY OF BRANCHIFERA. 



20. This family is composed of batrachians that always pre- 

 serve their branchiae, and resemble the tadpoles of batrachians 

 of the family of Urodela ; they have been regarded for a long 

 time as being in fact, the young of some large species of Sala- 

 mander ; but now, there is no doubt of their being perfect ani- 

 mals, and what is very remarkable, that possessing well developed 

 branchiae, they also have lungs, and are consequently completely 

 amphibious. These branchiae, which are placed in the ordinary 

 situation, have the form of tufts more or less ramified, and float 

 externally in the water. The lungs are sometimes provided with 

 a vascular net work as well developed as in any reptile, while in 

 others, their structure is very simple. The body of these animals 

 terminates in a long, vertical tail ; and their extremities are but 

 little developed, and often are partly wanting. Four genera are 

 known, namely ; the rfxolotus, the Menobranchus, the Proteus, 

 and the Siren. 



21. The AXOLOTLS, JlxolotMs, in every respect resemble 

 the tadpoles of Salamanders, 



that have acquired their fore 

 paws. Only a single species 

 has yet been discovered, the 

 rfxolotl of the Mexicans, 

 Siren pisciformis, (Fig. 39.) 

 which inhabits the lake in the 

 midst of which* stands the 

 city of Mexico. AXOLOTL. 



19. What are Monoporaa ? What are Amphiuma ? 



20. What are Brauchifera? What are their general characters ? What 

 are the genera of this family ? 



21. What are the characters of the Axolotls ? 



