7ß Art. 1, — M. Yokoyama : 



Living. — Central to Southern Japan. 



Family Csecidse. 

 Genus €/"F<;îj.^I, Fleming. 



î>7, i'œeunt vifreutn, Carpenter. 



PL III. Fig. 18. 



Caecum, citretnii. Carpenter, Monogr. Caecidae, Proc. Zool. Soc. Loucl., 1858, p. 432, 

 spec. 29. A. Adams, Ann. Mag. Nat. Hist., 1868, p. 364. Tryon, Man. Conch., 

 Via, p. 215, pi. 66, fig. 54. 



A single specimen of a small arched smooth shell, 2 niillim. in 

 length and about 0.5 millim. in diameter. The tube is somewhat 

 larger near the anterior end where it is more shar])ly curved than 

 in the other parts. 



A shell like this, having neither characteristic form nor 

 markings is extremely difficult to determine, especially when it is 

 a fossil. But as the presence of this species in the Japanese waters 

 has been already noted by A. Adams, I believe, I am justified in 

 assigning this to the same species. 



Fossil occurrence. — Shito. 



Living. — Central and Western Japan. 



Family Meianüdae. 



Genus IflFXAIVIA , Lamarck. 



98. Melanitt iiiponica, Smith. 



PI. IV. Fig. 1. 



Melania niponica. Smith, Descript. Some New Spec. Land a. Freshw. Shells a. Kern, 

 on Other Spec, found in Japan, Quart. Journ. Conchol., I, p. 118 (1876). Kobelt, 

 Fauna Moll. Extramar. Japon., p. 131, pi. 19, figs. 5-7, 10-14. 



Two decollated specimens, l)oth with the upper whorls broken, 

 The whorls grow rather rapidly and are ornamented with slightly 

 curved longitudinal costae, numbering sixteen on the penultimate 

 whorl and crossed by distant spiral cords (six on the penultimate), 

 the intersection-points being tul)ercular. On the l)ase there are 

 only spiral cords, the longitudinal costae ending at the periphery. 



