NATICA. 
267 
Bibliography, ^c. — This remarkable shell was first figured by Phillips, without 
a description, as from the Coralline Oolite of Malton, along with “ Echinus ” 
germinans and “ Clypeus ” semisulcatus . The distinction between the Coralline 
Oolite of the Malton district, and the Inferior Oolite of the Castle-Howard 
district was not made known in those early days. The type is at Leeds. 
The Pev. P. B. Brodie, in a paper “ On the Geology of the Neighbourhood of 
Grantham,”^ speaks of a very large Natica characteristic of the Inferior Oolite of 
Denton, of which casts only were known. This was described by Lycett as a 
new species under the title of N. Leckhamptonensis, with the following diagnosis : 
“ Spire elevated, whorls convex, the last enormously expanded, upper surface of 
the whorls rounded and sulcated ; aperture very effuse, orbicular. Only casts 
known. A gigantic species.” 
In 1854 Morris, with his usual sagacity, perceived the close connection 
between N. cincta, Phil., and N. Leckhamptonensis, Lyc., but, misled by Phillips, 
quotes it from the Coralline Oolite. Moreover, under the then prevailing 
impression that the Denton Limestone was Great Oolite (contrary to the opinion 
expressed by Brodie) he quotes it from the ‘‘Great Oolite” of Lincolnshire, as 
well as from the Inferior Oolite of Gloucestershire. 
Description .- 
Spiral angle .... 115° — 120°. 
Height of body- whorl to entire shell . . 80 : 100. 
Length about .... 100 mm. 
N.B. — The largest specimen known measures : Length, 116 mm. ; width, 
110 mm. 
Shell globosely angular, thick, nearly as wide as long, spire rather short, 
sub-euspiroid, apex probably blunt. Whorls (4 — 5) increase with great rapidity, 
causing an enormous expansion of the body- whorl. Sutural ledge very wide, and 
sloping downwards, so as to produce an inclined tabulate surface, which rises 
slightly to meet the keel at the angle of the whorl ; only canaliculate in the 
early stage. 
Body -whorl extremely ventricose, often richly marked by broad and curved 
lines of growth, and sometimes showing a kind of spiral line towards the middle. 
Aperture very effuse, hardly any sign of umbilicus, the shell-substance being 
very thick in this region (20 mm. in the type specimen). 
Varieties or Stages of Growth. — The figure (PI. XX, fig. 17) represents a small 
fossil such as may occasionally be found in the Oolite Marl, where casts of 
Natica cincta are fairly numerous. The proportions are almost exactly those of 
Natica cincta. It is more canaliculate than mature specimens of that species. 
The largest specimen of Natica cincta known was found in a pale chalky-look- 
^ ‘ Proc. Cottesw. Nat. Club,’ vol. i, p. 56. 
