1(j2 0)1 new Freshwater Shells from Japan. 



wliorls 3, the firsb flattened, microscopically spirally striate, 

 the last two caviiiafe above and subplanulate above the 

 carination, rather finely and closely obliquely costulate, the 

 last rounded at the periphery ; suture impressed ; umbilicus 

 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 upper 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. 



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

 greater tiian 40 metres {Dr. N. Annaiulale). 



Valvata annandalei, sp. n. ^ 



(PL IX. figs. 5, 5 a, 5 6.) 



Shell allied to V. biwaensis, but rather larger, with ex- 

 serted first whorl, coarser and more distant transverse costulse, 

 proportionately narrower umbilicus, which, in the present 

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

 shell, 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 mm. 



Aperture : alt. 3, diam. 2 mm. 



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

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



Class PELEGYPODA. 



Order TETRABRANCHIA. 



Suborder C N C H A C E A. 



Family Cyrenidae. 



Pis'uUum casertanum (Poll), forma lacuslris. 



Hah. 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 Palsearctic Pisidia, for 

 ills kind assistance in the above determination, and who 

 remarks that the specimens submitted to him are " rather 

 more oval than usual." 



