106 



GASTEROPODA OF THE INFERIOR OOLITE. 



91. Cbbithium tureis, Eudleston, 1884. Plate IX, fig. 15. 



1884. Cbbithium tueeis, Hudl. Geol. Mag., dec. iii, vol. i, p. 61, pi. iii, fig. 13. 



Description : 



Length . . . . .13 mm. 



Width ..... 4*75 mm. 



Spiral angle (mean) .... 20°. 

 Shell rather short, strongly turrited ; spiral angle somewhat convex Whorls 

 about twelve in number, flat and short, suture close. The ornaments are con- 

 spicuous. Seven spirals are counted on the penultimate, consisting of wavy lines 

 drawn out spirally, at considerable intervals, producing a sort of basket-like pattern. 

 The longitudinals are strong, and close together, especially in the upper part of 

 each whorl, but are on the whole irregular. 



Aperture subquadrate to oval, with a well-developed anterior canal. 

 Relations and Distribution. — This is more widely angled and less pupoid than 

 average specimens of G. Beanii, has a more complex system of ornamentation, and 

 is more strongly turrited. Very rare in the Yorkshire Dogger. 



92. Ceeithium (species). Plate X, fig. 1. 



Description. — Probable length 28 mm., width about one-fourth ; spiral angle 

 about 18°, and tolerably regular. The shell is scarcely turrited. The upper half 

 of the specimen is not sufficiently preserved for description. Whorls subtumid 

 with very close sutures, the sutural angle being but little inclined. The ornaments 

 consist of numerous fine spiral lines which are decussated at wide intervals by 

 irregular nodular costge, with a tendency to curve and incline from left to right. 

 These costas are usually the most developed anteriorly, and this causes the 

 preceding whorl to project somewhat over the succeeding one — a feature the 

 reverse of turriting. The number of the nodular longitudinals is about seven. 

 Aperture ovate with indications of an anterior canal. 



The specimen under consideration comes from the Inferior Oolite of Rodborough 

 Hill, and was regarded by Lycett as a Gerithium. It has some resemblance to G. 

 variculosum, Desl. (vol. cit., p. 210, pi. xi, fig. 46), a fossil of the Upper Lias of 

 Fontaine-Btoupefour. 



