﻿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 d'Orbigny's species more than do the Coker specimens. 



The Cotteswold specimens occur in the Upper Pisolite of Longfords, in the 

 Nails worth district. This also is in the Murchisojiae-zone, but presumably some- 

 what higher than the Coker beds. 



Genus — Cirrus, Sowerby, 1816. 



Re-defined as follows : — Shell sinistral, irregularly conical to subdiscoidal, often 

 turbinate; columellar area very short ; more or less umlnlicated . Spire acute ; spiral 

 angle more or less concave; whorls very irregular and variable, sometimes flat, 

 sometimes more or less tumid; sutures rather close. Whorls, rugosely ornamented; 

 large and sometime* spinous tubercles occur at the intersections of the spiral and axial 

 systems; varices sometimes occur, whilst the strive of growth are conspicuous and 

 oblique. Body-whorl ventricose ; aperture circular, expanding, and adherent. 



The above diagnosis would include Scsevola, Gemmellaro, which Fischer 

 classifies along with Cirrus under the Delphinulidre. Other authors, like Tate, 

 place Cirrus under the Solariida?. Sowerby thought that Cirrus and Euomphalus 

 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 Ham us', 'na . 



240. Cirrus Bthbridgii, Lycett, 1857. Plate XXIV, fig. 15. 



1857. Turbo Etheridgii, Lycett. The Cotteswold Hills, p. 125, pi. vi, fig. 3. 



Description ' 



Length . . . . .26 mm. 



Height of body- whorl to total length . . 42 : 100. 



Spiral angle .... 46°. 



Shell sinistral, conical, moderately turrited ; umbilicus contracted, spiral 

 angle slightly concave, spire acute ; number of whorls seven or eight, rather flat, 



