VON Jhering. — On the Ancient Connections of N.Z. 433 



All these facts induced me to take up the special study of 

 the Naiadae and the fresh-water fauna in general, as it proves 

 to be the most reliable guide to the knowledge of the geo- 

 graphy of our globe during Palaeozoic and Mesozoic times. I 

 am convinced that the importance of the fresh-water fauna in 

 this sense wall soon be generally acknowledged, and on this 

 point I fully agree with Professor Hutton, who so clearly 

 pointed out that the immigration of birds and frogs to Australia 

 must have taken place by different ways and at different times. 

 Moreover, I agree with Professor Hutton in thinking that an 

 ancient land-communication must have existed between South 

 America and New Guinea, Australia, &c., to account for the 

 close relations between the two territories in flora and fauna. 

 But, with regard to South America, my own researches, as 

 well as some other new discoveries, have led to so many new 

 and important points of view that some of Professor Hutton's 

 statements require alteration, and it is with reference to this 

 that these lines have been written. 



Professor Hutton says: "Our general results, then, are 

 that in early Mesozoic times New Zealand, eastern Australia, 

 and India formed one biological region, land probably extending 

 continuously from New Zealand to New South Wales and 

 Tasmania. During the Lower Cretaceous period a large Pacific 

 continent extended from New Guinea to Chile, sendmg south 

 from the neighbourhood of Fiji a peninsula that included New 

 Zealand. Nearly all the southern part of America was sub- 

 merged. This continent supported dicotyledons and other 

 plants, insects, land-shells, frogs, a few lizards and perhaps 

 snakes, and a few birds, but no mammals. In the Upper 

 Cretaceous period New Zealand became separated : the South 

 Pacific continent divided in the middle between Samoa and 

 the Society Islands, the eastern portion being elevated while 

 the centre sank. It ultimately became what we know now as 

 Chile, La Plata, and Patagonia." 



Let us examine now the relations of the faunistic and 

 geological evidence to this hypothesis. The investigation of 

 the fresh-water fauna shows a great agreement between Chile 

 and South Brazil. In Chile, as well as in South Brazil, the 

 waters, which are covered with Levma and Conferva, and over- 

 grown with rushes — Typlia, Sagittaria, Potamogeton , kc. — 

 contain besides Unio, Gyrana, Pisidiiim, species of Planorbis, 

 LimncBci, Ancijlns, Physa, Cldlina, and, in addition, several 

 genera of frogs and fresh-water fishes, and of Crustacea 

 Parastacus and ^glca. It is not known how far the alliance 

 of the lower animals goes ; but JEglea Icevis occurs in Chile 

 as well as in the Eio Grande do Sul, in both places with the 

 parasite TemnocepUala chilensis. This parasite is found here 

 also living on Parastacus and AmjniUaria canaliculata. In 

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