480 GASTEROPODA OF THE INFERIOR OOLITE. 
Bibliography, Sc.—The type is preserved in the Jermyn Street Museum. It 
cannot be said to correspond very closely with Lycett’s diagnosis. 
Description.—(Based upon the specimen in the Jermyn Street Museum.) 
Height 17 mm., width 9 mm. Shell cylindrical, but tapering anteriorly. The 
spire, consisting of about five whorls, is nearly flat and slightly sunken, but with a 
"prominent mammilliform apex of considerable size. The posterior margin of the 
body-whorl is flattened and encloses the spire, the dividing suture lying in a deep 
groove. The columellar lip is strongly twisted. 
The var. Weldonis is a fossil of much smaller habit, the usual height being 
8mm., width 4mm. It is also somewhat more pyriform in figure. 
Relations and Distribution.—Belongs to the section of Cylindrites which have 
sunken spires. Differs from Cy. mammillaris in the extensive flattening of the 
posterior margin of the body-whorl, and in the groove which divides this from 
the spire-whorls ; it is also rather broader in proportion to its length. 
The specimen in the Jermyn Street Museum, from the Inferior Oolite of 
Nailsworth, is the only one I have seen from the Cotteswolds. ‘The var. Weldonis 
is the most abundant Cylindrite in the Lincolnshire Limestone at Weldon and 
Ponton. 
432. CYLINDRITES MAMMILLARIS, Lycett, 1850 (not figured). 
1850. Cyttnprites Mamrinaris, Lycett. Ann. Mag. Nat. Hist., 2nd ser., vol. vi, 
p. 418. 
1853. — -—— — Proce. Cotteswold Nat. Club, vol. i, 
jos 72) 
Description.—Height 20 mm., width 8 mm. in a good-sized specimen. Shell 
cylindrical, elongate, sharply truncated atop. Spire flattened and sub-depressed, 
but the inner whorls have their upper flat surfaces visible, the first two or three 
of which are rounded into a mammillary knob. Aperture elongate with a strong 
columellar fold. 
Relations and Distribution.—This is an extremely narrow and cylindrical form, 
only differing from Oy. cylindricus, Morris and Lycett, in the salience of the 
mammillary knob and in the flattening, rather than depression, of the spire. 
There are two specimens of Cy. mamivillaris in the Brodie Collection from the 
Leckhampton Freestones. A variety, approaching Cy. cylindricus, also occurs 
sparingly in the Lincolnshire Limestone of Weldon. This has been quoted as 
Cy. cylindricus. 
