378 



their ratio to the Boina being that of 20 : 1, and to the Viperina of 

 4: 1. 



The identity of the creation in the different provinces of this re- 

 gion may he represented by the following examples, which will for- 

 cibly show the reason why I unite the ^Ethiopian shores of the Medi- 

 terranean especially with this region, instead of considering Spain and 

 Portugal as a part approximate more to Africa than to Europe, as 

 Schlegel did. • Eryx jaculus may be traced from the eastern half of 

 the shores of the Mediterranean, through the temperate part of Asia, 

 into the south of Siberia ; Tachymenis vivax from Egypt northwards 

 to Hungary. Further, the genus Zamenis is one of the most cha- 

 racteristic types of this region, — Z. atrovirens being spread along the 

 northern shores of the Mediterranean, Z. Cliffordii along the southern 

 ones, Z. hippocrepis and dahlii going entirely round this inland sea, 

 Z. ventrimaculatus reaching from Egypt through Kurdistan to the 

 south of the Himalaya, and, finally, Z. caudolinealus being a native 

 of Kurdistan. Coronella austriaca, more common in the parts north 

 of the Alps, is replaced in the south by C. girundica, in the north 

 of Africa by C. cucullata. Tropidonotus natrix, reaching into the 

 heart of northern Asia, is represented in North Africa by Trop. vipe- 

 rinus. Trop. hydrus appears to range still further towards the west 

 of Asia. Coluber qiiadrilineatus, common on the northern shores 

 of the Mediterranean and on its eastern islands, is again found in the 

 north of China. Coelopeltis, a true native of northern Africa, is 

 found in the Pyrenean peninsula. Pelias berus inhabits Ireland, 

 Scotland, England, Norway, Sweden, and all the central parts of 

 Europe, and is again found on the shores of the Lake of Baikal. 



The viperine snakes of this region exhibit generic differences on the 

 north and south of the Mediterranean, — on the former being found 

 Pelias and Vipera, on the latter Echis and Cerastes. But the 

 above stated facts sufficiently show that the lower part of Egypt 

 is to be united with this region as well as Algiers ; and I wonder 

 that Mr. Sclater leaves it uncertain whether he includes that part of 

 Egypt or not. A few true African forms intrude themselves into the 

 African parts of the region ; Echidna atricauda and mauritanica are 

 found in Algiers, and Naja haje, following in many varieties the 

 course of the African rivers, comes down with the Nile and reaches 

 the Delta. That Echis carhiata, more frequently met with in the 

 East Indian continent, is also found in Egypt, is a curious fact stated 

 by Dumeril and Bibron (vii. p. 1448) ; and as Schlegel mentions it 

 as being found also in the deserts south of the Caspian Sea, it quite 

 corresponds to the aforesaid range of Zamenis ventrimaculatus. 



The genus Triyonocephalus, which has its focus in the Indian re- 

 gion, is curiously enough represented by a single species (T. halys) 

 in the southern parts of Siberia, reaching into the north of the Cas- 

 pian sea. Thus of all the genera peculiar to the Indian region, 

 Trigonocephalus advances furthest northward, emitting moreover 

 another species (T. Blomhoffii) to Japan. 



Japan, that outpost of the palaearctic region, is not in the same 

 way peopled with palasarctic snakes as we find it with palsearctic 



