1908.] NATURAL SCIENCES OF PHILADELPHIA, 35 



Length 26, diam. above aperture 10, length of aperture 10 mm. 

 u 23, '' '' " 10, '' " 9.2 " 



Kitaura (Cape of Ojika), Ugo. Types No. 94,738 A. N. S. P., from 

 No. 1,444 of Mr. Hirase's collection. 



The obese shape, length about 2h times the diameter, is the chief 

 character of this local race. 



Pythia pachyodon n. sp. 



This species of the scarabceus group is nearly uniform blackish olive, 

 but with a blackish band below the suture and sometimes with more or 

 less brown suffusion. The sm-face is rather finely \vrinkle-striate, with 

 some widely spaced spiral lines. Spire angular on both sides, with 

 whitish streaks in front of the angle. Whorls 10. Base perforate or 

 umbilicate. Aperture with two stout parietal teeth and a strong 

 columellar lamella. Teeth in the outer margin irregular, three larger, 

 with two or three minute ones. 



Length 30.6, greatest diam. 18.5, antero-posterior diam. 13.5 mm.; 

 length of aperture 18.5 mm. 



Loochoo (Okinawa) and Oshima,in the Ryukyu Islands. Types No. 

 87,537 A. N. S. P., from Mr. Hirase. 



Pythia aegialitis n. sp. 



The shell is similar to P. 'pachyodon, but is copiously mottled with dark 

 brown on a pale corneous-yellowish ground; the markings sometimes 

 partially obscured when the surface is superficially worn. Teeth of the 

 inner margin as in P. 'pachyodon; three teeth in the outer lip. 



Length 25.3, greatest diam. 15.6, antero-posterior diam. 11, length 

 of aperture 16.7 mm. 



Loochoo (Okinawa) and Oshima, Ryukyu Islands. 



The specimens from Oshima are somewhat longer and comparatively 

 less wide than those from Loochoo Island. 



While closely related to the P. scarabceus group, which is composed of 

 very poorly characterized species, yet the two Ryukyuan forms do not 

 exactly agree with any of them, and it may be well to have definite 

 designations for them. 



Besides these forms, P. cecillei Phil, has been found by Mr. Hirase 

 at Hirado, Hizen, and P. 'nana Bavay was described from specimens 

 taken at Loochoo. 

 Pisidium japonioum n. sp. Fig. 1. 



The shell is subglobose, rounded-oval, with large, very wide, moder- 

 ately projecting rounded beaks; surface glossy, very finely, irregularly 

 striate; cuticle light yellow; valves very convex, not very inequipartite, 



