t^ DISTRIBUTION OF QUEENSLAND GASTEROPODA. 



Kuropean molluscan fauna, with those families now 

 inhabiting the Indian and Pacific Oceans, becomes- 

 uch closer, the most prominent forms represent- 

 nig the following genera : — Cancellaria, Fustis, Oliva^ 

 Valuta, Conus, Mitra, Rostellaria, Pleurotoma, Cyprcea, 

 Scalaria (Epitonium), etc. 



In these two periods, when the connection between 

 the Indian and Atlantic Oceans, across Northern Africa and 

 the basin of the Mediterranean, appears to have been wide 

 and complete, the climate must have greatly modified by 

 the flow of a vast current warmed in equatorial regions ; 

 and, though there are undoubtedly other causes that have 

 modified terrestrial climate since Miocene times, sufficient 

 stress does not seem to be given to the presence in recent 

 times of the two great barriers, the isthmuses of Suez and 

 Panama. These, by causing the equatorial current to be 

 deflected, first round Cape Agulhas and then round Cape 

 Horn, united with the influence of the west wind drift, 

 change it to a cold current on the southern and western 

 extremities of Africa and America. 



When we contrast the climate of British Columbia 

 with that of Labrador in the same latitude, we have 

 evidence of the striking results caused to the one by the 

 warm Japan current of the Pacific, and to the other by the 

 cold Labrador current that sweeps down from the Arctic 

 into the Atlantic. 



Wallace* expresses his belief in a former connection 

 of the Indian and Atlantic Oceans thus : — " We also know 

 that a little earlier, in Eocene times, tropical Africa was cut 

 off from Europe and Asia by a sea stretching from the 

 Atlantic to the Bay of Bengal, at which time Africa must 

 have formed a detached island- continent such as Aus- 

 tralia is now, and probably, like it, very poor in the higher 

 forms of life. 



Huxleyt also expresses the same opinion, as follows : — 

 *' There is ever}^ reason to believe that both Hindustan^ 

 south of the Ganges, and Africa, south of the Sahara, were 

 separated by a wide sea from Europe and North Asia during 



♦Island Life, p. 418. 



t Anniversary Address to the Geological Society, 1870. 



