THE NAUTILUS. 37 



Dimensions: 



Number of whorls ... . . . 5| 5 \ 5J- 



Type: Cat. No. 5087 of the writer's collection. Para types 

 have been deposited in the collections of the California Academy 

 of Sciences, and the Academy of Natural Sciences of Philadel- 

 phia, as well as the private collection of Allyn C. Smith (Cat, 

 No. 2236). 



Type Locality: Two miles north of Weed, Shasta County, 

 California; Allyn G. Smith, August 10, 1920; 22 adult speci- 

 mens, 9 juvenals. 



Remarks: From the evidently nearly allied loricata the pres- 

 ent species differs in its larger size and more simple toothing of 

 the aperture. In some ways it more nearly resembles germana, 

 but again is larger, has a much less tumid body whorl and dif- 

 fers strongly in being distinctly umbilicate. From columbiana 

 it differs in its compactness and smaller size, but it is neverthe- 

 less not very unlike this species on a greatly reduced scale. 



I have a small series of a similar but rather thinner-shelled 

 and more depressed race of Polygyra, collected in the high 

 Sierras of central California between Glenbrook and Al Tahoe, 

 by Mr. E. P. Chace in 1919. The differences are not great, 

 however, and they are apparently referable to the same species 

 as the Shasta County form. 



Near La Moine Mr. Smith collected a considerable series of a 

 peculiar race of Polygyra columbiana (Lea) which seems suffi- 

 ciently characteristic to be described. The ground was very 

 dry and no other species were taken there, but the Polygyras 

 were found almost in the water, under sticks and stones. 



Polygyra columbiana shasta new subspecies (Plate II, figs, 3-4). 



Description: Shell of moderate size, conic, thin; smooth, ex- 

 cept for the numerous and fairly strong incremental lines, 



