Fossils from the Bfiuxa Peninsula ;ni<l its Immediate North. 1,1 



53. Trophon nipponicus, Yokoyama. 

 Pl. III. Figs. 13, 14. 



Shell small, fusiform, with the height a little less than double 

 the diameter: whorls five or six. convex, distinctly angulate in the 

 middle, and furnished with rather ridge-like longitudinal ribs 

 which number fifteen to seventeen on the body-whorl; body-whorl 

 ventricose, somewhat longer than the spire ; aperture ovate; canal 

 slightly bent or almost straight, narrow, rather long. 



This species is closely akin to Trophon multicostalus Esch. 

 (Arnold. Pal. a. Str. San Pedro, p. 251, pl. VI, fig. 9) and 

 Trophon scalnriformis Gld (Arnold, pl. VI, fig. 10, Wood, Crag 

 Moll. Univ. I, p. 48, pl. VI, fig. 7, Suppl., p. 21, pl. III. fig. 10). 

 But it seems to be distinguished from both by distinctly angulated 

 whorls. Besides, Trophon muUicostatus has a more slender shape 

 and a less number of ribs (up to about thirteen), while Trophon 

 scalariformis shows a longer and bent canal. 



The largest of our specimens measures about 9 millim. in 

 diameter. 



Fossil occurrence. — Kanazawa Zone (Nojima and Teramae); 

 Koshiba Zone (Koshiba). 



54. Trophon muricatoides, Yokoyama. 

 Pl. III. Fig. 17. 



Shell small, fusiform, moderately thick; whorls very convex 

 separated by veiy deep sutures, longitudinally ribbed and spirally 

 striated; ribs rounded, strong on the upper whorls, but almost 

 obsolete on the body-whorl, separated by intervals of less breadth, 

 about thirteen in number on the penultimate whorl; spiral stria? 

 or threads equal, distant, five on all the whorls except the body- 

 whorl which has in addition more than seven on the base, which 

 are, however, somewhat finer: between these threads there are 

 invariably one or a few very fine interstitial lines. Aperture 

 inverted flask-shaped, with a short, somewhat bent canal. Inner 

 lip smooth. Outer lip thickened, smooth within. 



There is only a single specimen lacking the apex. The 



