286 GASTEROPODA OF THE INFERIOR OOLITE. 
216, Amperteya Morcuison1, Minster, 1844. Plate XXII, fig. 11. 
1844. Turbo Murcutsont, Miinst. Goldf., Petref., pl. exciv, fig. 10. 
Except that ours is a better specimen, showing the apical conditions, there 
seems no difference between the fossil from the Humphriesianus-zone of Bradford 
Abbas and the one figured by Goldfuss. No other British specimen is known to 
me. Amb. Obornensis, next described, is probably only a variety. 
217. AMBERLEYA OBORNENSIS, sp. nov. Plate XXII, fig. 10. 
Description : 
Length . ; : : . 25—35 mm. 
Length of body-whorl to total height . . 48:100. 
Spiral angle : 40°. 
Shell eucycloid, turrited. Spire pointed, with an obtuse apex. Whorls nine 
or ten, sutures very wide. The apical whorls smooth, full, and flattened towards 
the summit (the enlargement of figs. 6 and 11 is also suitable for this species), 
the succeeding whorls sub-biangulate, spirally ornamented, with the principal keel 
almost median. Close to the suture is a posterior row of tubercles, which are 
rather small and wide apart; next succeeds the flat sloping area, with axial striz, 
also rather wide apart; then the principal keel, which forms the angle of the 
whorl, the tuberculations being of moderate size; the lower median carina 
has the tuberculations still smaller and numerous; and below this, owing to the 
gaping of the suture, an additional carina, corresponding to the first spiral in the 
base, may frequently be detected. 
The body-whorl is angularly ventricose, the keel being situated rather high 
up, so as to shorten the posterior area, which together with the rest of the shell 
is axially striated, the strie being rather wide apart. 
The aperture is ovate-elongate, with a straight columellar lip produced 
anteriorly, somewhat after the manner of Purpuwrina, with a tendency to become 
more circular in the larger and more mature specimens. 
Relations and Distribution—Amberleya Obornensis, which is at least a good 
local variety of Amb. Murchisoni, although clearly a member of the goniata- 
group, has certain affinities with the more elegant forms of Amb. ornata, var. 
abbas. To a certain extent, then, it may be regarded as intermediate between 
the ornata- and goniata-groups, though its relations are mainly with the latter, 
This intermediate character corresponds with its stratigraphical position in 
