54 •^I't- 1- — M. Yokoyauia : 



Fusas arthrit l'eus. Valenciennes, Comptes Rendues, tome 46, p. 761. Bernard!, Jour. 



Concli,, 1857, p. 386, pi. XII, üg. 3. 

 Tritonium arthriticum. Schrenck, Moll. Amurl, u. d. nordjap. Meeres, p. 421. 

 Neptunea desjjecta. Tokuuaga, Foss. Env. Tokyo, p. 7. 



This is a very variable shell. But the greater part of the 

 fossils belongs to a form with keeled and nodulous shoulders, 

 although occasionally tliose with rounded ones are met witli. The 

 longitudinal ribs may be distinct or not. 



If this is really identical with Chrysodomus {Neptunea) despectus 

 Linné as mentioned in Tryon's Manual of Gonchology (vol. Ill, p. 

 116), then its distribution becomes circumpolar. 



Fossil occurrence. — Otake, Tega, Kioroshi, Shisui, Kamenari, 

 Shito. Oji and Shinagawa in Musashi. More or less frequent in 

 all the localities. 



Living. — Northern Japan (from Rikuzen nortliward). 

 Northern Sakhalin. Strait of Mamiya (Tartary). 



57. Chrysodoènus schrettchi, Yokoyama. 

 PI. II. Fig. 13. 

 Chrysodomus schrencki. Yokoyama, Foss. Miura Penin , p. 51, pj. Ill, tig. 1. 

 A few bad fragments. 



This species is very closely akin to C. pericochllon Sclirenck of 

 Northern Japan and probably a mere variation of the latter. 

 Fossil occurrence. — Shito. 

 Living. — Northern Japan (according to Prof. Yabe). 



Genus SIPHO, Ivleiii. 



5S. Sipho ohesi/'ortnis, Yokoyama. 



Sij)ho obesifonnis. Yokoyama, Foss. Miura Peniu., p. 52, pi. II, fig. 13. 



This species which I founded on a few siDecimens from the 

 Lower Musashino is rather frequent in the Upper. All 

 the examples which I have show the longitudinal plicae only 

 on the uppermost whorls, so that its resemblance to /Sip/io obesus 

 Sow. already alluded to in my w^ork above mentioned becomes 



