ALARIA. 137 
practically re-describes D’Archiac’s species, and, doubtless, the points of resem- 
blance with the Ponton fossil are tolerably close. In Al. pupxformis the shell is 
still more depressed, and the position of the spines is very different from that of the 
Ponton fossil. For all this we must hold that our var. spinifera closely approxi- 
mates to Al. pupeformis, D’Arch., as defined by Piette. On the other hand, the 
smooth or non-spinous variety of Al. pontonis is further removed from it. 
This species is rather characteristic of the Lincolnshire Limestone of Great 
Ponton, but I have not met with it elsewhere in the Inferior Oolite. On the other 
hand, it strongly resembles some of the Minchinhampton specimens of the 
trifida-group, and thus affords another link uniting the Gasteropod fauna of 
Great Ponton with that of the Great Oolite, both in the East of France and at 
Minchinhampton. (See ‘ Great-Oolite Moll.,’ Pl. iii, fig. 11.) 
56. ALARIA PRIMIGENIA, sp. noy. Plate VIL, fig. 3. 
Description : 
Length : : . 22mm. 
Width of body-whorl to height of shell 5 . 42: 100. 
Spiral angle about : . 34° 
Shell fusiform, turrited. Opening of the ell angle convex and obtuse. 
Number of whorls about eight; the apical and subapical whorls are without keel 
and apparently smooth; the last three whorls of the spire betray a very sudden 
increase, and are sharply carinated about the middle. There is no longitudinal 
ornamentation, and the spiral ornamentation, if ever it existed, is obliterated in 
the only available specimen. The keels of the spire-whorls develop pointed 
spinous swellings, which are very salient on the penult; these do not occur in 
axial order. 
The body-whorl presents but a moderate increase ; it is strongly bicarinate, 
and rather excavated; the base is very sharply marked off by the second carina. 
The wing is scarcely, if at all, palmate; the posterior keel produces a vigorous 
digitation, at first triangular in section, but becoming rounder, as it sweeps with 
a sharp upward curve considerably beyond the apex. The anterior digitation 
and canal-sheath are too much broken away for description. Other indications 
wanting. 
Relations and Distribution.—This curious species, though founded on a unique 
specimen, presents characters which easily separate it from any others heretofore 
described. The uncompressed spire, and the unsymmetrical arrangement of the 
spinous nodes, exclude this species from Spinigera, to which it has a certain 
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