134. GASTEROPODA OF THE INFERIOR OOLITE. 
The aperture is trapezoidal, the outer lip considerably produced, and each of 
the wing-digitations deeply channelled ; the canalis broad and comparatively short, 
since it curves sharply in a direction opposite to that of the anterior digitation, and 
to this circumstance much of the grotesque appearance of the shell (in common 
with other members of the trifida-group) is due. This also terminates in a slight 
expansion. 
Var. B. (Figs 6’ a, 6 b.) 
Description : 
Length . 5 : 5 . 19—27 mm. 
Spiral angle : 2 28" 
This form differs from the one re dasotibed in the comparative narrowness 
of the spiral angle and in the height of the whorls of the spire in proportion to 
their width. The slight differences of ornamentation are perhaps the result of 
accident. We may compare these forms in some respects to Al. gracilis, Lycett. 
Var. C. (Fig. 6” a.) 
Description : 
Spiral angle about : . 40° 
This specimen, which is deeply embedded in nab may be somewhat deceiving 
in appearance. It is shorter and more widely angled than the majority of speci- 
mens, and would do very well to represent the “‘ Chenopus”’? Philippi of Dunker 
and Koch. 
Relations and Distribution.—The Parkinsoni-zone of the neighbourhood of 
Burton Bradstock has yielded nearly all our specimens of Al. Lorieri. There is a 
specimen in the Bristol Museum (fig. 6 d), apparently a fragment of a large 
specimen of this species. Elsewhere it is very rare, small, and in poor preservation. 
Under such conditions Al. Lorieri or some member of the trifida-group may 
oceasionally be recognised in the Upper Division of the Inferior Oolite in the 
Cotteswolds. Some specimens of the trifida-group occurring in the Lincolnshire 
Limestone may possibly belong here likewise, though not the forms from Great 
Ponton (see Pl. VII, figs 1 a, 1 6, and 2), 
