54 LAND AND FRESH-WATER SHELLS OF N. A. [PART I. 



Lingual membrane with numerous arched rows of aculeate, 

 recurved, thorn-like uncini ; centrals simple, conical, pointed ; 

 laterals wanting. 



Fig. 90. 



Lingual dentition of Macrocyclis Vancouver ensis. 



Macrocyclis TancoiiTcrensis, Lea.— Shell widely umbilicatcd, 

 depressed, very slightly convex on the upper surface ; epidermis light 

 greenish-yellow ; whirls five, nearly flat above, protuberant and rounded 

 on the lower surface, lines of growth very minute, 

 Fig. 91. with crowded, microscopic revolving striae, the 



outer whirl expanding a little towards the aper- 

 ture ; umbilicus wide and deep ; aperture trans- 

 verse, somewhat rounded, flattened above by a 

 depression of the peristome near its junction 



,, ,. with the body-whirl, its edge tinged with rufous ; 



jUacroci/clin vanciiuctininis. .? i o o 



peristome thin, acute, slightly reflected at the 

 bnse of the shell, simple above, the two extremities approaching each 

 other, and connected by a thin callus, which covers the columella. Greater 

 diam. 31, lesser 26; height 14 mill. 



Helix concava, Binney, Bost. Journ. Nat. Hist. Ill, 372, pT. xiv (1S40), 



not of Say. 

 Helix vancouverensis, Lea, Am. Phil. Trans. VI, 87, pi. xxiii, f. 72 ; Obs. 



II, 87 (1839).— Troschel, Arch. f. Nat. 1839, 11, 21.— DeKay, N. Y. 



Moll. 45 (1843).— Pfeiffer, Symbotje, 11,41 ; Mon. Hel. Viv. I, 200; 



in Chemnitz, ed. 2, II, 14(5, pi. xciv, f. 21-23.— Binkey, Terr. Moll. 



II, 166, pi. XX.— W. G. Bi.NNEY, Terr. Mol). IV, 19.— Goulp, U. S. 



Expl. Ex. 36, f. 37 (1852).— Reeve, Con. Icon. no. 669 (18.52). 

 Helix vellicata, Forbes, Proc. Zool. Soc. Lend. Mar. 1850, 75, pi. ix, f. 1. — 



Chemnitz, ed. 2, II, 454, pi. cliv, f. 42-44. — Reeve, Con. Icon. no. 



673 (1852).— Pfeiffer, Mon. Hel. Viv. Ill, 155. 

 Macrocyclis vancouverensis, Tryon, Am. Journ. Conch. II, 245, pi. iii, f. 

 6 (1866). 



A west coast species, from lat. 56°, at Sitcha in Russian 

 America, to lat. 37° {Newcomb). Idaho (Cooper). 



