452 PROCEEDINGS OF THE ACADEMY OF [AugUSt, 



A COMPARISON OF THE LAND-SNAIL FAUNA OF KOREA WITH THE FAUNAS 

 OF JAPAN AND CHINA. 



BY HENRY A. PILSBRY. 



The compilation of a list of Korean land molliisks gives occasion for 

 a comparison of that fauna with the favmas of China and Japan. In 

 the list of Korean land snails published by Dr. O. von Moellendorff in 

 1887,^ some 26 species are catalogued; of this number, 7 are stated to 

 be common to Japan, 3 to China, and 2 (omitting the doubtful Helix 

 ciliosa) to both countries. 



The fruitful researches conducted by Mr. Y. Hirase have increased 

 the roll of known Korean forms to 58. This number is no doubt a 

 mere fragment of the total fauna; yet it is enough to show the domi- 

 nance of Japanese over Chinese forms in Korea. This preponderance 

 can only be explained by the theory that the submergence of the 

 straits between Kyushu and Korea is a geologically recent event. 

 From the large proportion of Japanese species existing in Korea, this 

 submergence may probably have taken place not earlier than the 

 Pliocene. 



Twenty-one Japanese species occur in Korea and Quelpart. Se\en 

 Chinese species occur in Korea and Quelpart, Four of these species 

 are common to Japan and China. The great preponderance of char- 

 acteristically Japanese over Chinese species is thus evident. Thirty- 

 two species and subspecies, out of a total of fifty-eight, are peculiar 

 to Korea including Quelpart. 



So much for the numerical relations of the species. The faunas may 

 also be compared qualitatively. All of the genera and subgenera of 

 the Korean fauna occur in Japan. In the Clausiliidce all the species 

 of Quelpart and Korea belong to Eiiphcedusa, a group of minor import- 

 ance in Japan, but extending farther north on the Asiatic mainland 

 than any other group of Clausilise. The genus Ganesella, well repre- 

 sented in Japan, seems to be absent in Korea, unless the species 

 described as Helix (Satsuma) gradata proves to belong to Ganesella, 

 which seems improbable. The absence of Ganesella and of Clausiliidoe, 

 other than Euphcedusa, are the most conspicuous discrepancies between 



* Jahrbucher d. Deutschen Malakozoologischen Gesellschaft, XIV, 1887, pp. 9-22. 



