54 Proceedings of the Royal Irish Academji. 



account for their presence — of vanished land in the areas now covered by the 

 Atlantic and Indian Oceans. 



As to the details of these ancient land tracts, much difference of opinion 

 has naturally been expressed. Wallace — as is well known to all students of 

 animal distribution — argued ('92) strongly against the theory of a continuous 

 continent across the Indian Ocean, even in Mesozoie times ; and among tlie 

 most recent writers on the subject, Sarasin '10, p. 57, denies the probability 

 of such a land area " in der spatereu Kreidezeit and im Tertiar." Blanford, 

 however, in his deservedly famous address ('90, pp. 88-99 j, while admitting 

 Wallace's contention that the facts derived from mammalian and avian 

 distribution afford but weak support to the theory, spoke convincingly in its 

 favour from the range of lower vertebrates and of mollusca, as well as from 

 the e.xtent of ancient ocean-basins, as shown by the range of marine fossils. 

 The great majority of modern students of distribution accept without 

 hesitation the principle of such a continent. As examples of the support 

 afforded to the theory by advance along different lines of inquiry may be 

 mentioned Germain's study ('09} of the mollusca of equatorial Africa, and 

 Ortmann's admirable essay '02) on the distribution of freshwaier Decapods. 



With respect to the fauna of the Seychelles, the question whether the 

 area of the arcliipelago maintained its latest connexion with Madagascar 

 and Africa, or with India and Ceylon, is of mucli interest and difficulty. 

 Ortniann (/. c, p. ;529) maintains that the connexion of Madagascar with 

 India was interrupted before that with Africa, and a similar view is expressed 

 in cue of the maps illustrating Gardiner's paper ('06, p. ;523), which shows an 

 early tertiary Afro-Malagasy peninsula, in which the Seychelles are seen 

 ue;ir the apex. Germain, on the other hand ('09. p. 1 72), imagines " une 

 longue peninsule Indo-Malgache qui s'effondra, ne laissant plus subsister au 

 debut du tertiare qu'uue chaine d'iles assez rapprochees. Madagascar est 

 completement isole et n'aura plus, par la suite, que des communications 

 temporaires avec I'Afrique." The series of maps given liy Gadow ('13) seem 

 to support in the main this latter view. In Perceval Wright's paper ('71) 

 on the flora of the Seychelles, an outstanding feature is the description of 

 a species of Nepenthes. This genus of " pitcher-plants " ranges from tropical 

 Australia to Madagascar, and is — as Wright pointed out — unknown in Africa. 

 Here again the Seychelles show affinity with the Oriental rather than with 

 the Ethiopian region. 



The Apterygota cannot be expected to throw much light on geographical 

 details such as the.se, for our ignorance of extinct members of the group is 

 very great. The predominance of Oriental species in the Seychelles fauna 

 has already beeu emphasized, and it is remarkable that, with the exception 



