384 GASTEROPODA OF THE INFERIOR OOLITE. 
Shell regularly conical, imperforate. Spire acute and about two-thirds the total 
height. Number of whorls seven, flat or very slightly concave, sutures distinct ; 
apical whorls smooth; in the later whorls a fine unornamented spiral belt bounds 
the anterior margin of each whorl; sinuous growth lines are conspicuous 
throughout. In the body-whorl these lines start from a granular spiral belt, 
situate at the posterior margin, and extend to the basal angle, which is sharply 
defined. Base rather flat and smooth; aperture subquadrate. 
Relations and Distribution.—The Weldon fossil differs from 7’. Dunkeri, of the 
Great Oolite,in the plain anterior belt at the base of each whorl, in this respect 
resembling Trochus Actea, d’Orb. But other considerations prevent us from 
regarding it as identical with d’Orbigny’s species. This is undoubtedly very near 
to T. Dunkeri, but even the rolling to which the Minchinhampton shells have been 
subject could scarcely have obliterated the belt entirely. The other differences 
might be fairly accounted for by difference of matrix. 
There are many varieties of T'rochus Weldonis, connecting with other forms. 
Common in the Lincolnshire Limestone at Weldon. 
323. TrocHus suBsTRIGOSUS, sp.nov. Plate XXXII, fig. 11, and ? fig. 4 (incomplete). 
But ef. Trocuus acantuus, d’Orbigny. Terr. Jur., vol. ii, p. 273, pl. ceexii, 
figs. 9—12. 
—  stricosus, Lycett. Suppl., p. 29, pl. xlv, fig. 12. 
—  acanruus, d’Orb. Cossmann, Bt. Bath., p. 286, pl. x, figs. 27, 28. 
N.B.—Although 7. acanthus, d’Orb., is a fossil of Port-en-Bessin, and 
consequently belonging to the true Bajocian or Upper Division of the Inferior 
Oolite, our fossils differ so much from d’Orbigny’s figures that I scarcely dare 
venture on absolute identification. On the other hand, there is a considerable 
resemblance between our fossils and 7’. strigosus, Lycett, from the Yorkshire 
Cornbrash. Now M. Cossmann, loc. cit., observes that, even supposing 1’. strigosus 
is not an actual synonym of 7’. acanthus, the name is pre-occupied. The only way 
out of these difficulties is to make a new species. 
Description (complete specimen) : 
Height : ; : : . 23 mm. 
Width : : : . 21 mm. 
Spiral angle . ; : / 160%. 
Shell conical, imperforate; spiral angle tolerably regular. Spire rather more 
than half the total height and acute. The total number of whorls is about eight ; 
those of the spire (except close to the apex) are flat to very slightly concave, with 
