AMPHIBIA. 525 



What is the 3rd FAMILY ? Where are they mostly found ? In what re- 

 spects do they resemble the Eel ? Do true SEA SNAKES visit the land ? 

 Are they easily caught? Can they live in fresh water? Are they venom- 

 ous? What is said by Dr. Cantor? What by the Rev. I. Williams? 

 What kind of scales have the Marine Snakes ? What species of true Ma- 

 rine Snakes are mentioned ? 



What is the 4th FAMILY ? How many gen. does it contain ? Are any 

 found on this continent? What is said of their teeth and shields? What 

 is said of the bite of the COMMON VIPER of Europe ? What remedies for 

 this bite are mentioned? What is said of the young, &c., of the Viper? 

 What of the Esping or Aspic ? What gen. contain the HOODED or SPEC- 

 TACLED SERPENTS? How characterized? What is said of their bite? 

 When do the hood and spectacles appear? What sp. are mentioned? 

 Which is the ASP OP CLEOPATRA ? What is said of the powers of jugglers ? 

 What new gen. has Dr. Cantor brought into notice ? What is said of the 

 Cerastes or Horned Snake ? What of the Death Adder ? What link does 

 this form? 



What is the 5th FAMILY ? By what characteristics are they distinguished ? 

 What is the type of this family ? How is it distinguished from the others ? 

 Describe the Rattle Snake. What is said of their habits and movements ? 

 What is their condition in mid-winter ? What is said of their food? Men- 

 tion the sp. found in N. A., also those of S. A. 



What gen. includes the Copper-heads ? Why are they to be especially 

 dreaded ? What sp. is found in the Northern and Middle States ? What 

 are its favorite resorts? What is said of the Water Moccasin? What of 

 the Lance-headed Viper? 



Name and trace those figured or mentioned on the Chart. 

 SECTION VI. 



FOURTH ORDER. AMPHIBIA, (Gr. 'a/ncpi^ios, amphibios^ having 

 a double life.) 



The Reptiles of which we have treated in the preceding sec- 

 tions, are covered with plates, shields, or scales. In those of the 

 present order, the skin is naked, smooth, and often moist, or lu- 

 bricated with a fluid secretion, which, in some cases, is acrid and 

 apt to irritate the skin of the persons who handle it. As in 

 snakes and lizards, the skin is frequently shed ; in some species 

 in shreds; in others entire. In some, as in the frog, the blood, 

 through the delicate vessels of the skin, as well as in the vessels 

 of the lungs and gills, undergoes those changes which are nec- 

 essary for the maintenance of animal liTe. This cutaneous res- 

 piration can, however, take place only while the skin is kept 

 moist ; the same remark may be made respecting the gills of 

 fishes, of tadpoles, and various Crustacea. To meet this exi- 



