NATURAL HISTORY OF CHINA — SOWERBY 355 



though true crocodiles are also found in American waters. Since, 

 however, there is one alligator to be found in the Old World, that 

 from the Yangtse, it is obvious that at one time this genus enjoyed 

 a very wide distribution in both the Old and the New Worlds, and 

 that in some way the Old and the New Worlds were connected at that 

 time. 



Paleontology has proved of the utmost assistance in determin- 

 ing how the distribution of fishes, both marine and fresh-water, 

 came about, though as yet nothing verj' important in the way of 

 fossil remains of this type of cold-blooded vertebrate has been found 

 in Chinese strata. Nevertheless, it is believed that China formed a 

 center of dispersal for the great carp family (CyprinMcu) , receiv- 

 ing at the same time an influx of Silurids, or catfishes, from the 

 region of the Indian Ocean. 



We may next consider for a while the question of the faunistic 

 areas that occur in China, or to which parts of China belong. Many 

 years ago a distinguished naturalist divided the globe up into great 

 faunistic regions such as the Palearctic, including practically the 

 whole of Europe, and central and northern Asia, the Ethiopian, in- 

 cluding Africa south of the Sahara, the Oriental, including India 

 and Malay, and the Nearctic, including North America. Since that 

 time it has become customary to go on dividing up these regions into 

 subregions or faunistic provinces, often, it must be admitted, with 

 but poor success. Notwithstanding this fact, we may make some 

 such attempt in the case of China, for, even if certain groups of 

 animals are not amenable to such a treatment, others undoubtedly 

 are, and it will greatly assist us in our examination of the Chinese 

 animals if we can discover the presence of such faunistic areas. 



As a matter of fact the task is not a difficult one, for some very 

 striking faunistic barriers occur in China. One of these is the great 

 Tsing Ling divide that extends from the highlands of the Tibetan 

 border through southern Kansu, and southern Shensi into Honan. 

 North .of this divide we have one group of animals, south of it 

 another. It forms the boundary line of the ranges of a large number 

 of both mammals and reptiles. For instance, we have already seen 

 how it marks the southerly limits of the range of the roe deer. At 

 the same time it forms the northerly limit of the range of the 

 muntjac, another small deer, and the porcupine. To the north of it 

 the animals are Tartarian in their affinities, to the south they are 

 oriental. In the Provinces of Kansu, north Shensi, Shansi, Chihli, 

 and Fengtien, the westernmost Province of Manchuria, we find such 

 animals as the allactaga, the suslik, the gazelle, the wild sheep, 

 animals which denote the intrusion of a Steppe fauna. At the same 

 time we have the roe deer, the wapiti, or red deer, the wild boar. 



