HG T. I WAKAWA. 



species, since they are connected by intermediate forms with those that 

 are devoid of the sculpture. A collection of stehnaphora from one and 

 the same locality may show an abundance of transitional forms from 

 smooth-surfaced individuals to others that have a distinct hammered-like 

 surface. Moreover this character of the shell is not peculiar to stehna- 

 ■phorà, being also met with in some individuals of oxijtropté. 



The embryo-shell (fig. 1) of this species is amber-colored and 

 extremely delicate, consisting of only three or four whorls with a very 

 low spire. Each whorl is perfectly rounded at the shoulder except on 

 the body-whorl which is somewhat angular along the middle and is 

 besides provided with exceedingly fine spiral lines. The aperture is 

 generally rounded above, while its basal portion at the lower end of the 

 columella is stretched out so as to form a short canal. As the shell 

 grows, the angle on the body-whorl generally disappears and the three 

 punctured lines characteristic of this species are developed (fig. 2 — 4) 



I have specimens of P. steimaphora from Awomori in Prov. Mutsu. 

 Kogawara Swamp in Prov. Rikuchu, Miyagi in Prov. Rikuzen, Poktt- 

 shima in Prov. Iwashiro, Kasumigaura in Prov. Hitachi, Tokyo, Aichi 

 in Prov. Owari, Tokushima in Prov. Awa, and Yayeyama Shima. Thus 

 it w ill be seen that the present species has a very wide distribution in 

 Japan, from Tsugaru Strait as far south as the Loo-choo Islands. At the 

 latter localit)', this seems to be the only species of Pahidina present, 

 according to a private communication of Mr. Kuroiwa 



Further it may be noted that this species is confined to shallow 

 water broadly exposed to light, such as rice-fields. So far as my obser- 

 vation goes, it never occurs in such places as lakes or rivers where 

 water is deep and cold. 



•1. Paladina ingalhicuia, Peeve. 



Pl. V, figs. 5—7. 



This is an exceedingly variable species, the several forms of which 

 are well represented and described in Kokelt's monograph. Notwith- 



