■28 
SCULPTURE OF WHORLS IN UNIVALVES. 
SuLCATE, when the whorls are furrowed with 
comparatively wide li'roovino's or channels, 
as in Phtnorhis alhu^ var. sitlatfa Taylor, 
and //e/i.v rottiiid((f<( AliUl. 
Fig. 4(3. — Example: Helix rotundata Miilier X 2, Hessle, Vorksliire, collected by 
Mr. J. D. Butterell. 
Carinate, when the whorls are strongly and 
acutely keeled, the carination is most usually 
at the periphery, as in Helix lapicidd L., and 
Helix terre!^fris Pennant. 
Fig. 47. — Example: Helix lapicida L., St. Vincent Rocks, Clifton, near Bristol, collected 
by Mr. J. W. Cundall. 
Clnuulate, or Lirate, when the whorls are furnished 
with spiral ribs or ridgings, as in Vijcloxtanid 
eleijdii.'! (Mull. ). 
Fig. 48. — Example: Cj'closlof/ia cle^’-iins (Midler), Preston Candover, Hants., collected 
by Mr. H. P. Fit/gerald. 
Decussate, Lacunose, Malleate, or Cancellate, 
when the spiral and transverse stri;o or plicm of 
the whorls form hy their intersection a series of 
somewhat ([uad.rangular and slightly hollowed 
areas; the intersecting lines form the style of 
sculpture termed Ueticulate when they cimss each 
other more or less ohlicpiely. 
Fig. 49. — Example: Li)nna'a pulustris var. lacunosa I’aylor, stream, 1 .cvciithorpe 
Pastures, near Leeds. 
Varicose, when the thickening and som ‘times con- 
sei|uent differeni colouring of the apmlnral 
margin, occurring in some shells, during rest 
periods in the process of growth, are not ah- 
sorhed hy the animal when growth is resumed, 
but remain crossing the whorls at regular or 
irregular intervals, as in Limnaja stiujiddis (L.), 
Helix lie mum /is L., etc. 
Fig. 50. — Example: Linuuva stagjialis var. variesata Ha/ay, PefTer Burn, I.ufl'ness 
Links, Haddingtonshire, collected by Rev. l)r, McMurtrie, F. R.S.E. 
The Umbilicus is the central cavity at the base of the shell and 
distinctly exists only when the columella is hollow, and is wide or 
contracted in correlation with the loose or constricted manner of 
