HELIX-CARACOLUS. 119 



wrinkled by incremental lines ; parietal callus under a strong lens 

 seen to be very densely, very minutely granulate, the granules 

 standing very closely on a bright, polished ground, not elongated 

 into wrinkles. Color, dark chestnut. 



H. exeellens Pfr. Spire concave- conoidal ; whorls slowly widen- 

 ing; base flattened, scarcely at all indented around the axis; surface 

 smoother and more shining than in H. caracolla ; peristome and 

 parietal callus orange-brown ; parietal wall under a strong lens 

 appearing nearly smooth, but really granulate, the granulation 

 excessively minute, much finer than in H. carocolla. Aperture 

 more triangular and narrower than in either carocolla or insititia ; 

 upper margin of peristome straight. Color dark-chestnuf, outer 

 whorl sometimes faintly olive-tinged. 



H. insititia Shutt. Spire rather straightly conoidal ; whorls more 

 rapidly widening than in the two preceding; base as in H. exeellens I 

 surface comparatively smooth and shining ; peristome white or 

 brownish ; parietal wall under a lens seen to be smooth or nearly 

 so. Aperture not so narrow or triangular as in H. exeellens ; the 

 upper margin of peristome curved. Color olive-green, inner whorls 

 brown or reddish ; sutures margined with yellow. 



H. sarcocheila Morch. Form of spire as in H. carocolla ; base 

 scarcely indented around the axis ; surface markings and coloration 

 as in carocolla ; peristome white or pale ; parietal callus more 

 decidedly rugose than in any other species, the granules elongated, 

 and larger than in H. carocolla. Aperture narrower than in H. 

 carocolla, but wider than that of H. exeellens. Upper margin of 

 peristome slightly curved. Color uniform olive-brown. 



H. angistoma Fer. Depressed, acutely carinated, lens-shaped, 

 nearly as convex below as above ; surface decussated, at least in 

 places ; whorls narrow, the several outer ones of equal width ; 

 aperture narrow, parietal callus strong. 



H. marginella Gmel. Smaller than most of the preceding ; spire 

 conoidal ; surface obliquely striate above, smoother beneath ; pe- 

 riphery carinated ; base convex, indented around the axis, which is 

 often umbilicate ; peristome narrowly expanded all around, thickened. 

 Color generally light bright-yellow, with conspicuous spiral dark 

 zones. 



