ATAPHRUS. 351 
Bibliography, §c.—Our Inferior Oolite specimens appear somewhat more 
elongated than the Bathonian types, yet not so dissimilar but what they may be 
referred to d’Archiac’s species. ‘ Nerita” bellulata, Bean, which I include here, 
is perhaps more close to Monodonta papilla, H. and D. (‘ Foss. Mont.-Bellay,’ p. 59, 
pl. im, fig. 1). Im fact, At. Labadyei, At. papilla, and At. Acmon have at least this 
feature in common, viz. that they are smooth trochiform shells, where the height 
and width are about equal. 
Description : 
Height of full-sized specimens. : . 15 mm. 
Width, about . : : c . 15—16 mm. 
Shell conoidal, subturbinate, smooth, tolerably thick. Spire elevated, the apex 
very obtuse. Whorls about six, subconvex and prominent, standing out well from 
the suture. The body-whorl is large, slightly depressed posteriorly, rounded at 
the angle, and subconvex in the base. Aperture restricted and almost circular, 
with a moderate columellar denticle, succeeded anteriorly by a very shallow sulcus 
or pit. 
Relations and Distribution.—Distinguished from At. Acmon by the prominence 
of the whorls. At. Labadyei, and the varieties therewith included, are also more 
widely distributed throughout the Inferior Oolite. 
Although in the main a Great Oolite species, At. Labadyei occurs in the Lower 
Division of the Inferior Oolite both in Dorset and in the Cotteswolds. It also 
occurs in the Clypeus-grit and in other localities and horizons; whilst in the 
Dogger it is represented by the var. bellulata, Bean. N.B.—Should there be any 
disposition to challenge the identification of At. Labadyei as an Inferior Oolite 
species, I would suggest that the forms from the Lower Division be classified as 
Ataphrus bellulatus. 
286. AtapHrus Acmon, d’Orbigny, 1850. Plate XXIX, figs. 11 and var. fig. 12 ; 
var. approaching Ataphrus papilla, 
H. and D., fig. 13. 
1850. Trocuus Acmon, d’Orbigny. Prod., i, p. 265. 
1852. — — _ Terr. Jur., vol. ii, p.278, pl. ecexiv, figs. 1—4. 
1873. Monopvonta Acmon, d’Orb. Tawney, Dundry Gasteropoda, p. 35 (27). 
1884. Atapurus Acmon, d’Orb. Cossmann, tage Bath., p. 281, pl. vii, figs. 9, 10. 
Cf. also — Heserri, Piette. Cossmann, op. cit., p. 281, pl. xvii, figs. 43, 44. 
Bibliography, §c.—This is essentially a Bajocian form, the types being from 
Bayeux and Porti-en-Bessin ; also abundant at Sully; all places where the fossili- 
