FORMS OF SHELL IN UNIVALVES. 2o 
Patelliform, wlieu the shell is limpet-shaped or 
conical, as in Ancylui^ Jiuvidtilis Mull. 
Fig. 2o. — Example: Ancylus JIu7fiatilis Miill. X 2, Sv.'arraton, Hants., collected by 
Rev. W. L. W. Eyre, M.A. 
Globose, when the shell approaches a sphere 
in .shape, as in Helix granulata Alder. 
P'lG. 27. — Example : Helix granulata Alder X 2, Ashley Downs, near Bristol, collected 
by Miss F. M. Hele. 
Trochiform, or Conoid, when the shell is conical, 
with a flattened base, as in Helix terrestris 
Pennant, Hyalinid fulm (Miill.), etc. 
Fig. 28. — Example ; Helix terrestris Pennant, Dover, collected by Rev. J. W. Horsley, M. A. 
Lenticular, or Lens-shaped, when the shell is of 
a depressed form, with a more or less acute 
peripheral margin, as in Helix Idyicidd L. 
Fig. 29. — E.vample: Helix lapicida L., St. Vincent Rocks, Clifton, near Bristol, collected 
by Mr. J. \V. Cundall. 
Depressed, when the spire is only slightly raised 
above the body- whorl, as in Helix itdhi L., 
Hydlinid nitidiihi (Drap.), etc. 
Fig, 30. — Example : Helix itala L., Tenby, S. Wales, collected by Air. W. H. Boland. 
Dlscoidal, or (^uoit-shaped, when the shell 
has the spire flattened or even sunk in 
the centre, as in the Flduorbes, Vdlcdtd 
cristdtd Miiller, etc. 
Fig. 31. — Example : Planorbis corneus var. albina Moq., Mill pond, Lifi'ord, near King’s 
Norton, Warwickshire, collected by Mr. J. Madison. 
Gibbous, when the whorls are transversely 
swollen, usually near the aperture, as 
occasionally occurs in Limnad duriculdrid 
(L.), Limnwd stdyndlis (L.), etc. 
Fig. 32. — Example: Liiiintea auricularia var. ^ibbosa Taylor, pond, Moorlown, near 
Leeds. 
ScALARiFORM, wheu the whorls are almost separated from each 
other, as occasionally observed in Helix porndtia L., Helix 
