NEW FRESH-WATER MOLLUSKS FROM 

 NORTHERN ASIA 



By ALAN MOZLEY 



Walter Rathbonc Bacon Scholar, Smithsonian Institution 



(With One Plate) 



During the years 1932 and 1933 a journey was made through cer- 

 tain parts of Siberia and northern Kazakstan, under the grant of the 

 Walter Rathbone Bacon Scholarship ' of the Smithsonian Institution. 

 The object of this expedition was to investigate the moUuscan fauna 

 of the region, and in the course of working up the material collected, 

 several forms have been discovered which appear to be undescribed. A 

 report on the fauna as a whole will appear at a later date, but in the 

 meantime it appears to be desirable to place on record a brief descrip- 

 tion of the new forms, which is given below. 



VALVATA ANTIQUILINA, n. sp. 



Plate I, fig. 4 



Shell of moderate size for members of this genus, length 6.4 mm, 

 broadly conical ; surface smooth, with minute crowded lines of growth ; 

 whorls four and seven-eighths, convex, very slightly flattened ; aperture 

 subcircular, very slightly angulated along the superior margin, lip con- 

 tinuous, attached to the preceding whorl for about 0.6 mm. The dimen- 

 sions of the type are as follows : Length 6.4 mm, greater diameter 

 5.9 mm, lesser diameter 5.2 mm, aperture length 3.1 mm, aperture 

 width 2.5 mm. 



Type. — U.S.N.M. no. 469212, collected at Lake Khomotenoye, Aj- 

 Bulat drainage basin, Siberia. This is approximately 370 kilometers 

 southeast of Omsk. 



This species has some resemblance to both V. piscinalis (Miiller), 

 and V. antiqua Morris, and in many respects is intermediate between 

 these two species. It differs from most forms of V. piscinalis in having 



' Created through a bequest to the Institution by Mrs. Virginia Purdy Bacon 

 " to be used in estabHshing a travehng scholarship, to be called the Walter Rath- 

 bone Bacon scholarship for the study of the fauna of countries other than the 

 United .States of America." 



Smithsonian Miscellaneous Collections, Vol. 92, No. 2 



