82 ANNALS NEW YORE ACADEMY OF SCIENCES 



Recently Pilsbry has given an excellent static treatise of the distribu- 

 tion of non-marine mollusca of South America. He has combatted the 

 separation of Guiana, Brazil and Patagonia during past times. In this 

 far, I agree with his conclusions, but his data do not alone warrant them, 

 because the highland environments in Guiana and Brazil are very much 

 alike, and hence similar forms are to be expected from a common older 

 .stock, even if these regions had been isolated from each other during part 

 of the Mesozoic and Tertiary times. His static evidence certainly almost 

 if not completely destroys that of Ortmann for a Guiano-African con- 

 nection, but he has unfortunately located his Brazilian-South African 

 connection exactly in the region where we have given extremely strong 

 geological evidence against such a view. The entire coast of Brazil in 

 this region is fringed by marine Cretaceous, which alone would force this 

 connection to have disappeared at least in the early Cretaceous. Besides, 

 the "Pernambucan fan" is strong evidence against any Paleozoic connec- 

 tion in this region. There is also so much other geological evidence against 

 the building up of a land-mass across the great ocean depths of the South 

 Atlantic that we may consider Dr. Pilsbry's view highly improbable, at 

 least until some dynamic and more careful field studies have been made 

 on the non-marine mollusca of the regions in question. His actual paleo- 

 telic forms which were distributed are not yet absolutely known to have 

 originated in this purely hypothetical Gondwana Land. 



Ants 



Von Ihering has even used the distribution of the ants to prop up his 

 Archhelenis theory. He states that we still see the ingression of Bolivian 

 ants into Brazil. These ants are supposed to have come by the way of 

 Antarctica from the eastern hemisphere. This evidence appears to me to 

 be of little weight, because the ants have had a highland since the Per- 

 mian, over which they could have crawled or flown into Brazil. Further- 

 more, practically nothing is known of the ants which live in the high- 

 lands of central Matto Grosso. If one may hazard a guess, I would sug- 

 gest that a detailed study of the ants would show an invasion from Brazil 

 toward the Andes and not vice versa, after the elevation of the mountains 

 in Tertiary times. 



Corals 



Gregory has shown that the Miocene corals of the Mediterranean re- 

 semble the living corals of the West Indies. This is not, I believe, evi- 

 dence that the West Indies were directly connected with the eastern 

 hemisphere, because the larvas of these corals may have drifted over by 



