306 GASTEROPODA OF THE INFERIOR OOLITE. 
a plain carina. The sutures are close. Fine spiral granulation is shown both in 
the flanks and base of some of the Cotteswold specimens. 
Body-whorl angular and similarly ornamented; base rather flat, and probably 
spirally striated. Aperture subcircular; lip rounded and thickened on the 
columellar side, which is very short; outer lip slightly angulated. 
Relations and Distribution.—The points wherein H. Oppelensis differs from 
H. Bertheloti have been already indicated. The Cotteswold shells may be said to 
differ from @’Orbigny’s species more than do the Coker specimens. 
The Cotteswold specimens occur in the Upper Pisolite of Longfords, in the 
Nailsworth district. This also is in the Murchisone-zone, but presumably some- 
what higher than the Coker beds. 
Genus—Crrrus, Sowerby, 1816. 
Re-defined as follows :—Shell sinistral, irregularly conical to subdiscoidal, often 
turbinate ; columellar area very short ; more or less umbilicated. Spire acute; spiral 
angle more ov less concave; whorls very irregular and variable, sometimes flat, 
sometimes more or less tumid; sutures rather close. Whorls rugosely ornamented ; 
large and sometimes spinous tubercles occur at the intersections of the spiral and axial 
systems ; varices sometimes occur, whilst the striex of growth are conspicuous and 
oblique. Body-whorl ventricose ; aperture circular, expanding, and adherent. 
The above diagnosis would include Scxvola, Gemmellaro, which Fischer 
classifies along with Cirrus under the Delphinulide. Other authors, like Tate, 
place Cirrus under the Solariide. Sowerby thought that Cirrus and Huomphalus 
merged into each other, and that both were distinct from Delphinula. 
It will be convenient to commence with those forms, which, from their more 
regular spiral angle and trochiform shell, most nearly approach Hamusina. 
240. Cirrus Erneripen, Lycett, 1857. Plate XXIV, fig. 15. 
1857. Turso Eruerter, Lycett. The Cotteswold Hills, p. 125, pl. vi, fig. 3. 
Description : 
Length : : ‘ . 26mm. 
Height of body-whorl to total length . 2 42° 200: 
Spiral angle : 5 d 46°. 
Shell sinistral, conical, moderately turrited; umbilicus contracted, spiral 
angle slightly concave, spire acute; number of whorls seven or eight, rather flat, 
