A. E. Ortmann — Climatic zones- in Jurassic times. 259 



Nautilus only is in some way related to it, but we have reason 

 to suppose that the habits of the Ammonites- were generally 

 the same as in Nautilus. From the latter animal recently J. 

 Walther * has inferred a peculiar fact in regard to the 

 Ammonites, namely that the living animals were restricted in 

 their distribution to narrow limits within the littoral district of 

 the sea, but that after the death of the animal the empty 

 shell, provided with air chambers, rose to the surface of the 

 sea and was transported by wind and currents. Thus the 

 shells were dispersed all over the earth and were deposited as 

 fossils in parts where the living animal did not exist. Accord- 

 ing to this peculiarity, he says that the Ammonites are true 

 "characteristic fossils," as they are to be found in all the 

 deposits of the same time on the whole earth. 



This supposition is without any proper foundation, even in 

 case the Ammonites possessed the same habits as Nautilus. 

 The living Nautilus is not restricted to a limited range, as 

 supposed by Walther (1. c. p. 513.) It is true, the living 

 animal has been found up to the present time only in a few 

 localities, but even these localities, scattered in the Pacific 

 Ocean,f indicate a more extensive distribution within this 

 area, and I may add, that I have ample reason for believing 

 that the living Nautilus is also an inhabitant of the eastern 

 coast of Africa.:]: This distribution would not be strange ; on 

 the contrary, the range of Nautilus would be in accordance 

 with that of the other animals belonging to the littoral Indo- 

 Pacific fauna. Further, the empty shells of Nautilus occur only 

 in the Indo-Pacific Ocean, the statement made by Walther 

 (1. c. p. 513), that their distribution is an universal one, being 

 incorrect, and thus the distribution of the shells does not 

 occupy a wider area than that of the living animal. On the 



* Einleitung in die G-eologie als historische Wissenschaft II. Lebensweise der 

 Meerestiere 1893, p. 509ff. 



f For instance : Amboina, New Guinea, New Hebrides, New Caledonia, Fiji 

 Islands. 



^ During my stay on the east coast of Africa I collected positive information 

 about the existence of living Nautilus near the harbor of Dar-es-Salaam. I was 

 shown two very fresh specimens of the shell, and the owner of one of them told 

 me, without being asked, that he found the shell on the beach after a high tide 

 with an animal inside, which he had much difficulty in extracting. Hearing from 

 me that the animal was a very valuable one, he was sorry not to have preserved 

 it, and farther on, he spent his leisure time in search for another specimen, and 

 that without my knowledge, apparently intending to sell it to me if possible. 

 He was not successful. I trust wholly in the correctness of his information, as I 

 received others from him regarding zoological objects which proved to be trust- 

 worthy. Later on I found out that the animal is generally known among the 

 negro fishermen living on the beach. According to their own words, it lives 

 "kisiwani," ("among the islands," situated off the coast), and in " maji mingi " 

 ("deep water," for the coast-negro 10 to 20 fathoms are " deep water"). The 

 animal is not rarely captured by them, but it is always thrown away as of no use 

 for them. 



