HELIX. 161 



Subgenus AGLAIA, Albers. 



Shell umbilicate, orbicularly convex, striatulate, banded ; 

 whirls 4^-6, the last deeply deflexed in front ; aperture lunate- 

 ovate, very oblique ; peristome thickened, expansively reflexcd, 

 white, its margins approaching, that of the columella dilated, 

 reflexed, free, partially covering the umbilicus. 



Animal (of H. fidelis) : color dull ochre, slaty towards the 

 tail ; coarsely granular upon the neck ; but from a line running 

 from the dorsal line, where it issues from the shell, to the mouth, 

 the granules diminish, and are succeeded by coarse, undulating, 

 interrupted ridges, radiating in every direction from the aper- 

 ture, and terminating in a line nearly marginal ; edge simple. 



Helix Udells. Gray. — Shell iimbilicated, orbicularly snbconoid ; 

 epidermis light yellow or brownish on the upper surface, with a black or 

 chestnut colored, revolving band visible on 



the four outer whirls, the lower surface Fig. 278. 



dark chestnut, sometimes uniformly black; 

 suture distinct, impressed ; whirls seven, 

 rounded, spirally striate, with minute, deli- 

 cate, impressed lines, the strife of increase 

 very distinct ; peristome reflected below, 

 simple above, thickened; aperture ovate, 

 banded within; umbilicus open, a little 

 contracted by the reflection of the peri- Helix fidelis. 



stome ; base flattened-convex. Greater 

 diam. 34, lesser 30 ; height 20 mill. 



Helix fidelis, Gray, Proc. Zool. Soc. July, 3834, 67. — Pfeiffer, Mon. Hel. 



Viv, I, 338 ; in Chemnitz, ed. 2, I, 321, pi. Ivii, f. 12-13.— Muller, 



Syn. Test, anno 1834 promulg., 8 (1836). — Reeve, Con. Icon. no. 



657 (1852).— W. G. Binney, Pac. R. R. Rep. VI, 111 (1857) ; Terr. 



Moll. IV, 14. 

 Helix nuttaUiana, Lea, Am. Phil. Trans. VI, 88, pi. xxiii, f. 74; Obs. II, 



88 (1839); Troschel, Arch. f. Nat. 1839, II, 229.— Binney, Bost. 



Journ. Nat. Hist. Ill, 369, pi. xii (1840) ; Terr. Moll. II, 159, pi. 



xviii.— DeKay, N. Y. Moll. 46 (1843).— Gocld, U. S. Expl. Exped. 



Moll. QQ, f. 38 (1852). 

 Aglaja Jidelis, Tryon, Am. Journ. Conch. II, 311, pi. v, f. 8 (1866). 



Humboldt Bay, Cal., to Vancouver's Island, Oregon. From 

 Mt. Shasta the specimens are half as large as usual. 

 1 1 October, 1868. 



