282 Proceedings oj- the Royril Trhli Acculemy, 



The reptilian fauna of the Atlantic Islands is almost altogether 

 Eui'opean in its character, and shews scarcely any trace of an American 

 relationship. 



The Lacertidte, of "which family a few species occur on tlie 

 islands, are not found at all in America ; and the only genus of the 

 Seincidse -which inhabits the Atlantic Islands is also unrepresented in 

 the Xew World. It is only among the Geckonidse that "we find a link 

 across the ocean. Two species of Tarentola inhabit the Canary 

 Islands ; -while an allied form has been met -with in the TTest Indies. 

 To judge from the general range of the genns, the migi'ation has taken 

 place from Xorth Afiica to America. 



Among this same family of Geckonid», -we meet -with some inte- 

 resting instances of discontinuous distribution : thus Gymnodadi/Jus 

 mauriticanus lives in northern Africa, "while the closely allied 

 G. ly Orlignyi inhabits Chili. Only a single species of PhylJodaciylus 

 occurs in Europe, the remainder of the genus being confined to South 

 America, South Africa, ^Madagascar, Socotra, and Australia. Semi- 

 dadylus, another genus of the same family, seems to be an exceedingly 

 ancient one, to judge from its distribution. One species inhabits the 

 borders of the ^Mediterranean, while a closely related one is found not 

 only in South America, but also in M^adagascar and South Africa — -riz., 

 S. mahouia. The other species of the genus are distributed over the 

 Cape Yerde Islands, Socotra, St. Helena, South India, [Mauritius, the 

 islands of the western Pacific, 'West Africa, Ceylon, Persia, South 

 America, and East Africa. 



The Anguidse, which are frequently limbless or only provided 

 ■with rudimentary limbs, are almost entirely confined to America. 

 The genus Ophisannts, however, which has a species in ]iIexico, and 

 another in eastern Xorth America, is represented by one species in 

 southern Europe, and by another in the Himalayan mountains. 



Of much interest, from a geographical point of "view, are the 

 buxrowing Amphisbaenidae, which, generally limbless, often spend 

 their entire existence undergi'ound in ants' nests. That such species 

 are not likely to be conveyed across an ocean by accidental causes, in 

 the manner described by Wallace and others, is e"vident. Xow this large 

 family of sixty-five species is quite confined to America, Africa, and the 

 Mediterranean region. As very few species range into North America, 

 while not a single one has been discovered in Asia, the hypothesis of a 

 land- connection across the Atlantic explains the geogi'aphical distiibu- 

 tion of this family better than any other theory. Take, for example, 

 such a case as the genus Anoj)s. There are two species, A. 



