74 Zoological Society :— 



it first. It was also the second Stoastoma found, though not de- 

 scribed till long after S. Gouldianum, the latter in Sept. 1849 and 

 the former in Oct. 1850 ; for Adams at that time was inclined to 

 treat it as a mere variety ! Stoastoma JVilkinsonceanuniy Ad. Cont. 

 Conch, p. 148 ; Cat. Phan. p. 233. 



WlLKINSON^A GOULDIANA, Chitty. 



Hab. The backwoods in Manchester's highest mountains, north- 

 ern region. Stoastoma Gouldianum, Ad. See Mon. Stoast. Adams, 

 1849, p. 5 ; Cat. Phan. p. 232. 



Var. a. Ad. 

 Same habitat. 



Labrum not so much produced above. Aperture more cupped 

 and expanded in proportion. (See, as above.) 



Var. b. Chitty. 



Hab. Trelawny, still further north. 



Is much smaller than var. «., and labrum and aperture are mini- 

 ature of S. Gouldianum proper. 



Height 0-03.5, greatest breadth 0*073, least breadth 0-058. 



WiLKINSONiEA SCHOMBURGKIANA, Chitty. 



Hab. Moreland, Manchester. 



Form, subdiscoidal. Colour, semitransparent very pale horn. Sculp- 

 ture, lines of growth very apparent ; counting from the suture, there 

 are five less prominent and then one very prominent rounded spiral ca- 

 rinee, three less and one very prominent, two less and one very pro- 

 minent, two less and one prominent, three less and one very promi- 

 nent, and eight less, gradually becoming finer round the umbilicus : 

 visible on the upper whorls, three less, one prominent and two less. 

 Spire, much depressed, with considerably convex outlines. Whorls, 

 3f rds, well rounded but flattened at the lower part ; suture very 

 lightly impressed. Aperture, constricted at more than the width of 

 the last whorl from the labrum, about 0*015, and then convexly 

 rounded externally and concavely internally ; widely expanded, de- 

 flected below, subsemielliptical. Labrum, leaves the body at about 

 50°, very much thickened and reflected ; pure white ; deeply scol- 

 loped by the strong spiral carinse, which form five blunted points. 

 Labium *, nearly straight above, curved below abruptly to the right 

 and then to the left back again ; much below the plane of the labrum, 

 joining it at about the constriction of the aperture above, but rising 

 to the plane below. Umbilicus, narrow and deep. Labral lamella, 

 very slightly rounded, and projecting at its junction with the labrum, 

 narrow and slightly produced below. Operculum, very broadly 

 margined all round by a wide convex fold and a raised lamella on 

 the labral side like the capital italic D ; very deeply concave, with, 

 in the hollow, three or four rounded raised ridges crossing diagonally 

 from right above to left below, which are finely decussated diagonally 



* It is singular, that out of only ten specimens, every one should have the 

 operculum which partially hides the labium. 



