147 



No. 16. More or less reddish, often with a wliito stripe at the upper edge or 

 the last whorl ; with a brown epidermis, which is more or less interrupted bv na. 

 ked spiral stripes, whicli are often numerous : wrinkles conimcncin]^ in some be. 

 fore, in others after the end of the penult whorl, in some, narrow and well defined, 

 often nearly obsolete, especially on the back of the last whorl ; transverse striiE fine 

 but rather deep ; rarely a little wrinkled near the umbilical keel, which is well de- 

 veloped: spire well elevated : whorls and aperture as in No. 15: umbilicus about 

 half as wide as the aperture. Operculum with a spiral lamella of six or seven 

 whorls, moderately sloping outwards, with the upper margin moderately reflected 

 externally. »• 



Mean divergence about 120°; height .68 inch ; greatest breadth 1.04 incli • 

 least breadth .83 inch. 



In No. IG' the wrinkles are obsolete. 



No. 16" has the wrinkles mostly on the penult whorl. 



No. 17. Shell white with more or less reddish, pure white on the last whorl 

 next the suture; with a rich brown epidermis: transverse stria; rather coarse; 

 wrinkles minute but well defined, occupying more or less of the last whorl ; um- 

 bilical keel well developed : spire much elevated : whorls five and one-third ; last 

 whorl moderately depressed above ; suture well impressed : aperture large, subor- 

 bicular, somewhat acute above ; lip rather thin, slightly sinuated below by the 

 umbilical keel : umbilicus half as wide as the aperture. Operculum a little con- 

 cave ; spiral lamella with seven or eigtt whorls, rather wide, curvately reflected, 

 but not concealing the intermediate space. 



Mean divergence about 110°; height .9 inch; greatest breadth 1.08 inch • 

 least breadth .87 inch. 



No. 18. Shell white with a greenish brown epidermis, or reddish with a dark 

 brown epidermis : with the transverse striae extremely coarse ; with irregular coarse 

 but not deep wrinkles on the upper part of the last whorl ; with some more or less 

 distinct striiE oil the last whorl: spire well elevated: whorls about five and one- 

 third, scarcely depressed above, with a well impressed suture : aperture large, sub- 

 orbicular ; efFusc, pointed and advanced above ; lip slightly sinuate above, moder- 

 ately thickened ; in the white variety thin and sharp on the right side : umbilicus 

 a little more than half as wide as the aperture. Operculum flat ; lamella with six 

 or seven distinct whorls, rather narrow, moderately reflected. 



Inhabits the middle parts of Manchester. 



Mean divergence about 120° ; height .88 inch ; greatest breadth 1.23 inch • 

 least breadth 1 inch. 



No. 18' is probably an accidental variety, with tiio last whorl deflected below 

 the middle of the penult whorl ; the aperture and the umbilicus are consequently 

 contracted : in the other details it agrees with the type. 



No. 19. Shell white with a brown epidermis : with deep transverse strite ; with 

 indistinct spiral strite ; not wrinkled ; umbilical keel obsolete : spire moderately 

 elevated : whorls five ; last whorl scarcely depressed above ; suture well impressed . 

 aperture suborbicular, effuse, pointed, and advanced above : lip well thickened : 

 umbilicus nearly two-thirds as wide as the aperture. Operculum rather concave ; 

 lamella with about seven whorls, of medium width, nearly perpendicular except 

 that the thickened upper margin is moderately reflected. 



