162 On new Freshwater Shells from Japan. 



wliorls 3, the first flattened, microscp/ncaUi/ spirallij striate, 

 the last two cavinate above and sul)|)Ianuhite above the 

 cariiiation, ratlier finely and closely obliquely costulate, the 

 last rounded at the periphery ; suture impressed ; uinbih'cus 

 deep, occupying; in breadth about one-seventh of the total 

 diameter of the shell ; base of shell convex ; columella 

 margin descending in a vertical curve, extending above into 

 a restricted, but rather thick, parietal callus, which joins it 

 with the uj)per margin of the labrum, and gives to this last a 

 continuous appearance; labrum acute ; aperture subcircular; 

 operculum whitish, thin, multispiral, with central nucleus. 



Alt. 3-75, diam. maj. 5, diam. min. 3*5 ram. 



Aperture : alt. 2*25, diam. 2-25 mm. 



llab. Luke Biwa, Japan ; on a muddy bottom at depths 

 greater than 40 metres [Dr. X. Annandale). 



Valvata annandalei, sp. n. 

 (PI. IX. figs. 0, 5 a, ob.) 



Shell allied to V. Uwaensi'n, but rather larger, with ex- 

 serted first whorl, coarser and more distant transverse costulae, 

 projiortionately narrower umbilicus, whicli, in the present 

 species, occupies about one-eigiith of the total diameter of the 

 sliell, and in possessing a basal carina situated near the 

 circura-umbilical region ; moreover, the aperture is more oval 

 and proportionately much larger than in V. hiwaensis. 



Alt. 5, diam. maj. 5*25, diam. min. 4 ram. 



Aperture : alt, 3, diam. 2 mm. 



Ilah. Lake Biwa, Japan; on a muddy bottom at depths 

 greater than 40 metres [Dr. N. Annandale). 



Class PELECYPODA. 



Order TETRABRAXCIIIA. 



Suborder Conchacea. 



Family Cyrenidae. 



Pisidiam casertanum (Poli), forma lacusLris. 



Ilah. Abundant on a muddy bottom in Lake Biwa at 

 depths greater than 40 metres, and not found in shallower 

 water. 



The author must here tender his thanks to Mr. B. B. Wood- 

 ward, the well-known expert in the Paliearctic Pisldia, for 

 his kind assistance in the above determination, and who 

 remarks that the specimens submitted to him are '' rather 

 more oval than usual." 



