ScHARKF — Some lli'iiutrkti on the Atkoiti^ I^rohfon. 287 



America arc very closely related to those of Africa, wliile tliey differ 

 enormously from the North-American ones. A similar resemblance in 

 the fish-fauna of Africa and Soxith America has already been alluded 

 to; and the author concludes that there can be no other interi^retation 

 of these phenomena but that of a former land-connection between 

 Brazil and Africa. He assumes this connection to have been mainly a 

 Mesozoic one ; though he admits that it may have persisted until 

 Oligoceue times (B, p. 135). 



This large continental mass, which partly filled the southern 

 Atlantic, must have covered vast areas of the ocean, including 

 islands like St. Helena and rernando de I^oronha. These may 

 therefore represent remnants of the Atlantic continent. Their fauna 

 and flora would naturally be of extreme interest in throwing light 

 upon this subject. But although the animals and plants of these 

 islands have been investigated by competent naturalists, who have 

 declared them to possess either African or South American affinities, 

 Wallace's decided views in favour of the accidental transmission of 

 sjjecies greatly influenced opinion regarding tlieir origin. Even 

 WoUaston expressed himself against the theory that St. Helena had 

 ever formed part of a continent (B, p. 530). However, a large number 

 of species inhabiting that island are peculiar to it ; and Wallace himself 

 recognizes that the insect fauna is suggestive of a very great antiquity 

 (B, p. 300). 



Mr. E. Smith — one of the more recent writers on the molluscan 

 fauna of St. Helena — detects a greater resemblance to the South- 

 American fauna than Avas suspected by either Forbes or Wollaston. 

 All the same, arguing from the isolated position of the island and the 

 depth of the surrounding ocean, he docs not believe in its having been 

 formerly joined to South America. Still more recently, Dr. Kobelt 

 discusses the problem again from a study of the molluscan fauna of 

 the island, and comes to the conclusion that St. Helena is a hist relic 

 «f a Mesozoic continent (E, p. 202). 



In the very interesting account of tlie fauna of " Fernando de 

 ■Noronha " by Mr. Eidley, the writer does not enlarge upon the 

 possibility of this group of little islands having formed part of a 

 ■continent, though the occurrence of a subterranean amphisbajna {A. 

 Ridlcyi) and of a peculiar fresh-water snail {Planorhis noyhonensin) 

 might have suggested to him a different explanation of their origin 

 than that of accidental importation. At any rate. Dr. von llicring is 

 confident tliat Fernando de Norouha has had an ancient land-commu- 

 nication with South America on the west, and with Africa on the east. 



