S6 GASTEROPODA OF THE INFERIOR OOLITE. 
collection at the British Museum. Beyond the fact that it is a Purpwrina very 
little else can be made out. 
Morris and Lycett observe that P. elaborata has likewise been obtained from 
the Inferior Oolite (middle division) of the Minchinhampton district (p. 64), where 
specimens are said to be larger and more satisfactory (p. 117) than those from 
Scarborough. It has not been my lot to see any of these, though there are 
specimens of Purpurine from the Oolite-Marl devoid of any very distinctive 
features. Those authors speak of this species (p. 64) as occurring in the Inferior 
Oolite of Normandy, an allusion probably to P. bellona, which occurs on a higher 
horizon. On the whole P. elaborata must be regarded as a generalised form, 
which disputes with P. bellona the title to rank as the representative of the genus. 
In describing the really beautiful shells from the Sowerbyi-bed of Bradford Abbas 
under this title I have endeavoured to utilise an old name rather than invent a 
new one. 
Description : 
Length of a well-grown shell. . 20 mm. 
Ratio of width to length ‘ : » og HOW: 
Length of body-whorl to entire shell 2 06R 100: 
Spiral angle : 5 206": 
Shell ovate-conoidal, apex acute. Whorls about five or six; posterior area 
tabulate, sides moderately tumid. The ornaments consist of about eighteen stout 
longitudinal cost, which are feebly developed on the tabular area, rise up into 
spinous nodes on the keel, and are strong and regular in the flanks of the whorls. 
The coste have a tendency to die out anteriorly on the body-whorl, a feature by 
no means confined to this species. The costz decussate with regular and closely- 
set spirals, which extend down to the base of the shell; no spirals are seen on the 
flat area. 
Aperture oval to subquadrate. Columella moderately reflexed so as to produce 
anteriorly a wide and shallow groove towards the point. Umbilical slit scarcely 
indicated. 
Relations and Distribution.—The group of the Purpurinas to which P. elaborata 
belongs presents many features in common, and there can be no doubt that the 
several species run into each other to a very great extent. In fact, according to 
a lumping view of the case we might regard P. elaborata-bellona as one widely 
distributed species characteristic of the Inferior Oolite, and also represented in the 
Great Oolite of this country. When a badly preserved specimen turns up little 
more can be done than refer it thus. There is no doubt, however, that average 
specimens of D’Orbigny’s P. bellona, which is fairly abundant in the ‘ Oolithe 
ferrugineuse ” of Normandy, present characters which on the whole differ con- 
stantly from average specimens obtained in the lower zones of the Inferior Oolite 
