III. CONTRIBUTIONS TO THE STUDY OF THE FRESH 

 WATER FISHES OF THE ISLAND OF FORMOSA. 



By Masamitsu Oshima. 

 Of the Institute of Science, Government of Formosa. 



(Plates XLVIII-LIII.) 



Introduction. 



The Island of Formosa, lies in the western Pacific Ocean, between 

 the Southern and Eastern China Seas and is separated from the Chinese 

 mainland by the Formosan Strait, which has a width of about ninety 

 miles in its narrowest part. It is two hundred and five miles long and 

 from sixty to eighty miles broad, having seven hundred and thirty-one 

 miles of coast-line and an area of 13,429 square miles, being thus nearly 

 of the same size as Kiushiu, the southernmost island of Japan proper. 



The island is traversed throughout its length by a fine mountain 

 range, which reaches an altitude of from 8,000 to 12,000 feet, Mt. 

 Niitaka (14,270 ft.) stands in the middle and Mt. Silvia (12,480 ft.) 

 in the north. In addition, along the eastern shore there are coast 

 ranges of considerable height, the bases of which form magnificent 

 cliffs from fifteen to twenty-five hundred feet high. Thus the middle 

 p(i.rt and the eastern side of the island are mountainous, while the west 

 is covered by fertile plains. 



Because of the above mentioned topography, there are very few 

 rivers on the eastern coast, while on the western coast there are many 

 of considerable length, namely, Tamusui, Hozan, Koro, Daian, Daito, 

 Dakusui, Seira, Shinkobi, Sobun, and Shimo-Tamusui, of which the 

 last-named is the largest. In addition to these, there is a lake called 

 Jitsugetsutan (Lake Candidius), which has a small outlet into the 

 River Dakusui. 



Until a comparatively recent date the Island of Formosa was a 

 "terra incognita" to the naturalist, and the fresh-water fishes, which 

 are especially valuable as confirming the geographical relationship 

 between isolated islands and continents, were quite unknown. 



When Albert Giinther published his " Catalogue of Fishes " in 1859- 

 1870, he had only sixteen species of Formosan fresh-water fishes to 

 12 — DEC. 16, 1919. 169 



