Dr. A. Giinther on the Geographical Distribution of Reptiles. 225 



a guide, Mr. Sclater states the following primary divisions of the 

 earth's surface : — 



I. Palcearctic Region (Regio Palsearctica). 



Extent.— Mv\c?i, north of the Atlas; Europe; Asia Minor; 

 Persia and Asia generally, north of the Himalaya Range ; upper part 

 of the Himalaya Range (?); Northern China, Japan, and the Aleutian 

 Islands. Approximate area of 14,000,000 square miles. 



II. Mthiopian or IVestern Palceotropical Region (Regio 

 iEthiopica) . 



Extent. — Africa, south of the Atlas Range ; Madagascar ; Bour- 

 bon ; Mauritius ; Socotra, and probably Arabia up to the Persian 

 Gulf, south of 30^ N. lat. Approximate area of 12,000,000 square 

 miles. 



III. Indian or Middle Palceotropical Region (Regio Indica). 



Extent. — India and Asia generally, south of the Himalayas ; Cey- 

 lon; Burmah, Malacca, and Southern China ; Philippines ; Borneo ; 

 Java; Sumatra and adjacent islands. An area of perhaps 4,000,000 

 square miles. 



IV. Australian or Eastern Palceotropical Region (Regio 

 Austrahana). 



Extent. — Papua and adjacent islands ; Australia ; Tasmania and 

 Pacific Islands. An area of perhaps 3,000,000 square miles. 



V. Nearctic or North American Region (Regio Nearctica). 



Extent. — Greenland, and North America down to centre of 

 Mexico. Area of perhaps 0,500,000 square miles. 



VI. Neotropical or South American Region (Regio Neotropica). 



Extent. — "West India Islands ; Southern Mexico ; Central Ame- 

 rica, and whole of South x\merica ; Galapagos Islands ; Falkland 

 Islands. Estimated area of about .5,500,000 square miles. 



The notices devoted to each region will show how great is the con- 

 formity which this most natural division and the definition of the 

 limits of the regions exhibit in Herpetology. 



I. Palcearctic Region (Regio Palcearctica). 



Characteristic forms. — {Calamarial) coronella, {Tachgmenis'!) 

 virax, (Simotesl) diadema, Rhinechis, Zamenis, Ckorisodon, Ccelo- 

 2)eltis, Eryx, Petius, Vipera, Echis, Cerastes. 



Form common to India. — Trigonocephalus. 



This region is at once distinguished by the small number of generic 

 forms and of species : great variety of amphibian hfe is produced only 

 by the sun of the Tropics, and dependent upon a simihir variety of 

 the vegetative world. Where the soil is covered with social plants, 



Ann. ^ Mag. N, Hist. Ser. 3. Vol. iii. 15 



