Notes on the Paludina-Species of 

 Japan. 



By T. Iwakawa. 



Professor of Zoology, Higher Normal School, Tokyo. 

 With PL V. 



While engaged in rearranging the shell collection of the Imperial 

 Museum at Uyeno, Tokyo, I have found among it a pretty extensive 

 series of native Paludina specimens from localities ranging from Awomori 

 at the north-eastern extremity of Hondo as far south-west as the island 

 of Shikoku. Advantage was taken of this opportunity to make a sys- 

 tematic study of the genus, but as I soon felt the desirability of having 

 more materials in order to arrive at satisfactory results, and especially 

 as the labelling of localities appeared in some cases unreliable, I 

 have given special attention to obtaining fresh paludinas while on a 

 collecting tour in the northern provinces during the summer of 1890. 

 On that occasion, I enjoyed the agreeable company and valuable 

 assistance of Prof. C. Ishikawa and also the cooperation of Messrs. K. 

 Matsuura and I. Horikawa, assistants to the Zoological Department of 

 the Imperial Museum. Two hundred and eighteen fresh specimens were 

 brought home from different localities, chiefly in the provinces of Mutsu, 

 Kikuchu, Rikuzen, and Iwashiro. These, added to the old specimens 

 of the Museum, formed a material of over five-hundred, which number 

 further received considerable augmentation through the kind gifts of 

 several friends in different parts of the country. For specimens from 

 middle Japan I am especially indebted to Mr. M. Kawatsura of Kami- 

 suwa, Prov. Shinano, and to Mr. Y. Nawa of Gifu. Mr. Kuroiwa of 

 the Normal School of Naha has kindly sent me specimens from Yaye- 

 yama Shima, Loo-choo Islands. To all the gentlemen above named I 

 wish here to tender my thanks. 



