1905.] NATURAL SCIENCES OF PHILADELPHIA. 113 



ones nearly flat, the last two or three more convex. The aperture is 

 ovate, the outer lip, arched forward in the middle, retracted above. 

 Columella arcuate, moderately calloused. 



Length 24.5, diam. 6.3, length of aperture with peristome 5.2 mm. 



Length 23.3, diam. 6.5, length of aperture with peristome 5.7 mm. 



Hahajima, Ogasawara. No. 88,310, A. N. S. P., from No. 1,605 

 of Mr. Hirase's collection. 



So far as I know, this species has been recorded hitherto only from 

 Australia. I have not been able to compare Australian specimens, 

 and various important details, such as the number of whorls, are not 

 mentioned in the published descriptions. No critical comparison with 

 them of the specimens from the Bonin Islands can therefore be made 

 at this time. 

 Phorcus borealis n. sp. PI. IV, figs. 29, 30. 



Shell narrowly but deeply umbilicate, depressed, moderately solid, 

 whitish ashen; the surface rather dull, smooth except for faint growth- 

 strife, and on the base excessively fine, close, subobsolete spiral striae. 

 Spire low, convex-conic, the periphery obtusely subangular, the base 

 flattened. Whorls 4, convex, the last very wide. Aperture oblique,, 

 rounded-ovate, pearly with brilliant green reflections within, the lip 

 with a wide, dull, whitish margin. Columella arcuate, rather thin; 

 parietal callous thin. Umbilicus bounded by an angle. Operculum, 

 corneous, multispiral, the edges of the whorls slightly free. 



Alt. 4, diam. 5.5 mm. 



Kushiro, Kushiro, Hokkaido. Types No. 87,776, A. N. S. P., from 

 No. 1,583 of Mr. Hirasc's collection. 



This little Gibbuloid snail is shaped like Norrissia norrisi of Cali- 

 fornia. It does not resemble any Japanese species known to me. 

 Monilea nucleolus Pils. 



See these Proceedings for 1904, PI. 6, figs. 58, 58a. The locality, 

 Yakujima, Osumi, was omitted in the original description. 

 Ethalia guamensis Quoy. 



This species was described from a single specimen procured at Guam 

 by the naturalists of the Astrolabe.'' The figure represents the shell 

 as having the umbilicus partly closed by a callous, but neither figure 

 nor description show whether this partial closure is effected by (1) a 

 callous pillar partly filling the umbilicus, or (2) by a mere reflection 

 of the columellar margin, vaulting over a free umbilical cavity. A. 

 Adams and subsequent authors have taken the first alternative and 



'' RoieUa guamensis Q. and G., Zool. Astrolabe, III, p. 267, atlas PI. 61, fig.s. 32, ?Z 

 S 



