CERITHIUM. 159 
anterior portions of the whorls. Spirals on the base of the body-whorl scarcely 
granulated. Other indications wanting. 
Relations and Distribution.—C. Leckenbyi may, perhaps, be regarded as an 
unusually fine development of C. Beanii, from which, however, it differs in its 
greater size, more marked turriting, and in the details of its ornaments. Rare in 
the Dogger. 
80. Certraiuy Brann, Morris and Lycett, 1851. Plate IX, figs. 5 a, 5 b. 
1851. Cxrrrruium Beanu, M. aad L. Great Ool. Moll., p. 112, pl. xv, fig. 5. 
1884. — os -— Hudleston, Geol. Mag., dee. iii, vol. i, 
p- 59, pl. iii, figs. 10 and 11, 
Compare also for varieties 
CERITHIUM PUPMFORME, Koch and Dunker. Beitr., p. 33, pl. ii, fig. 10. 
Bibliography, §e.—Although described by the authors of the ‘ Great Oolite 
Mollusca’ as occurring near Scarborough, their type, | have very little doubt, 
came from the Dogger at Blue Wyke. 
Description of the Dogger or type-form : 
Length varying from : . 9—12 mm. 
Width «. : : : . 3—3°5. 
Spiral angle of apex ; 2, 20°. 
Do., anterior portion of spire ; 15°. 
The above dimensions are only approximate, regard being had to the 
numerous varieties. 
Shell small, more or less pupoid, turrited; whorls from ten to twelve, 
narrow, and rather flattened. The anterior whorls are ornamented by five 
tuberculated spirals, of which the third and fifth are least prominent. Sometimes 
the tubercles become slightly confluent, in which case there is a tendency to the 
formation of axial costs, especially in the upper part of each whorl. ‘The upper 
row of spirals is strongly tuberculated, though this feature is subject to some 
variety. 
Body-whorl slightly compressed, and not exceeding one-third the total length 
of the shell; ornaments as in the anterior whorls of the spire. Base spirally 
striated. Aperture subquadrate; columella short, and terminated by a short 
but rather deeply cut anterior canal. 
Relations and Distribution—Vhe Yorkshire specimens are to a certain extent 
sui generis. Those from the Lincolnshire Limestone, and the very rare specimens 
from the Inferior Oolite of the Cotteswolds, vary considerably from these types. 
