258 
GASTEROPODA OF THE INFERIOR OOLITE. 
was from the Scarborough Limestone, the latter from the Dogger. Since Morris 
and Lycett refigure the specimen from the Scarborough Limestone as the type, 
we may so regard it. This form is not rare in all three zones of the Inferior 
Oolite in Yorkshire, being most abundant in the Dogger. 
Description : 
Spiral angle .... 90° — 92°. 
Height of body- whorl to entire shell . 70 : 100. 
Length about . . . .25 mm. 
Shell longer than wide (5 : 4), oval, apex sharp. Whorls (6 or 7) smooth, 
convex, and narrow, the width of the penultimate being nearly twice the height of 
the spire. Upper part of each whorl flattened and moderately canaliculate. Body- 
whorl relatively large, angular, scarcely tumid, in some specimens marked by fine 
curved lines of growth. 
Aperture widely oval, and with the columella slightly encrusted; rarely 
indications of an umbilical fissure. 
Relations and Distribution. — The above description may be taken as typical of 
the whole group to a certain extent ; hence it will be sufficient to show in what 
way the other named forms differ from this one. Since it seldom happens that 
the angles of the whorls are so well preserved as in the figured specimen, the 
Buspiroid character of Natica adducta is not always recognised, the more so as the 
ledge is rather narrow. 
Besides its occurrence in all three horizons of the Inferior Oolite on the 
Yorkshire coast, I have typical specimens of Natica adducta from the lower part 
of the Lincolnshire Limestone in Mid-Lincolnshire, and again from the Pea-grit 
and Oolite Marl of the Cotteswolds. Mr. Witchell quotes it from the 
Gryphite-grit. 
Var. Oppelensis, Lycett, 1857. Plate XX, fig. 2. 
1857. Natica Oppelensis, Lycett. Cotteswold Hills, p. 123, pi. i, fig. 4. 
This is a small variety of N. adducta, which occurs in the Cotteswold Sands of 
the Nailsworth district (Opalinus-mne) . Although quite as much an Euspira as 
any one of the Naticidse in the Cotteswolds, Lycett described this form as a 
Natica. It has exactly the same angle of whorl as Natica adducta, and the same 
ratio of body-whorl to entire shell, viz. 7 : 10. The spiral angle is a little 
over 90°. The encircling lines, on which Lycett relied for specific characters, are 
seen on some specimens not on others. These, it is believed, are mainly due to 
conditions of preservation, where the inner shell layers are exposed. It is 
