56 Art. 1. — M. Yokoyama : 



Fossil occurrence. — Shito. 



Living. — Northern and Central Japan. 



61. Sip/tonaiia f roch u/ its, (Reeve). 



PI. n. Fig-. 15-18. . 



Siphonalia trochulus. Dunker, Index Moll., p. 1(3. Pilsbry, Catalogue, p. 30. Tryon, 

 Man. Conch., Ill, p. 136, pi. 55, fig 373. Yokoyama, Foss. Miura'Peuin., p. 54, 

 pi. Ill, fig. 14. 



Buccinnm trochulus. Keeve, Concb. Icon., spec. 7. 



Neptimea {Siphonalia) trochulus. Kobelt in Mart. u. Cliem. Syst. Concb. Cab., IIL pt. 

 3, p. 128, pi. 42, figs. 2, 3. 



The great variahility of this shell is well shown by numerous 

 examples, both young and adult, brought from several localities. 



A greater part of the examples shows either no longitudinal 

 plicae or very weak ones only on the body-whorl. But occasion- 

 ally specimens are met with which possess such, though weak, also 

 on the penultimate whorl. 'J'he canal is generally more or less bent. 

 The inside of the outer lip is usually smooth, but now and then 

 transversely ridged, in which case the lip is thicker. 



Siphonalla stearnsii, a species founded by Pilsbry (Catalogue, 

 p. 29. pi. II, figs. 1, 2) on a shell closely resembling the present 

 one in shape, but having the upper whorls longitudinally plicate 

 may possibly be one of the many forms of S. trochulus. 



Fossil occurrence. — Utake (frequent), Kamenari, Shisui 

 (frequent), Tega, Shito (very frequent). Oji and Shinagawa in 

 Musashi. Lower Musashino of Naganuma. 



Living. — Central Japan. 



62. Sipho^ialia kelleffii, (Forbes). 



PI. V. Fig. 1. 



Siphonalia kellettii. Pilsbry, Cat., pp. 30 and 168. Tryon, Man. Concb., Ill, p. 134, pi, 

 54, fi. 352. Liscbke, Jap. Meeres concbl., I, p. 38, pi. Ill, figs. 3, 4, Carpenter, 

 Eeport II, p. 663. 



Fimis kellettii. Forbes, Proc. Zool. Soc. Lond., 1850, p. 274, pi. IX, figs. 9, 10. 



A large specimen 140 millim. in height, though not quite 

 well preserved. The species is readily recognized by the fusiform 



