6 SUPPLEMENT TO GREAT OOLITE MOLLUSCA. 
large, rounded, attenuated at the base; the canal is short and oblique; the aperture is 
much contracted at the two extremities. 
Geological Position and Locality. ‘The Great Oolite of Minchinhampton, collected by 
E. Witchell, Esq., of Stroud. 
Pourpuromea insienis, Lyc. Tab. XXXI, fig. 2, 2a. 
PURPUROIDEA INSIGNIS, Lye. Cotteswold Hills Handbook, &c., pl. 7, fig. 8, a, 6. 
Testa turbinata, ovata, inflata, spira exserta, anfractibus 5 subangulatis, tuberculis 
depressis (9 in ambitu), anfractu ultimo magno inflato, plerumque sine tuberculis ; apertura 
magna ovata, canali leviter excavato 
Shell turbinated, ovate, inflated; spire half the length of the aperture; volutions (5) 
slightly angulated and flattened upon their upper surfaces, with nine small, depressed 
tubercles upon each volution ; the last volution large, ventricose, rounded, the latter half 
of the circumference being destitute of tubercles, and having only oblique folds of growth; 
aperture ovate, columella with an umbilical groove; the basal notch is only slightly 
defined, the junction of the columellar and outer lips forming a gentle curvature. The 
shorter, angular spire, depressed tubercles, and ventricose figure of the last volution, serve 
to distinguish it from P. xodulata, the species to which it is most nearly allied. The 
expanded base, wide, shallow, or obsolete notch, and rounded columella, so constant in all 
the species of Purpuroidea, appear to me to justify a generic separation from the recent 
Purpura, to which they have been reunited by some French paleontologists of eminence. 
The genus Purpurina of D’Orbigny, exemplified by his type P. Bellona, is separated 
from Purpuroidea both by the figure of the aperture and by his description, in which the 
contracted basal canal is insisted upon; other so-called examples of Purpurina, in the 
‘Paléontologie Frangaise,’ as Ornata, Bianor, Biva, and Bathis, have, together with a 
thin shell, a lengthened, subulate figure and an entire aperture ; these should be placed with 
the Littorinidze, and should range by the side of Améerleya, figured and described in the 
first part of this monograph. I am inclined to claim for Amderleya a more important 
position than that of a sub-genus. 
The Great Oolite species of Purpuroidea have, however, been merged by Professor 
Morris (‘ Catalogue’) and by Dr. Oppel (‘ Juraformation’) with Purpurina. 
Geological Position and Locality. The Great Oolite of Minchinhampton Common, 
associated with other species of the same genus. 
Crritu1um Batnonicum, Zyc. ‘Tab. XLIV, fig. 19. 
Testa parva subconica, apice obtuso, anfractibis latis, paucis, pldanis ; costis (7) rectis 
magnis, oblusis, striisque cingendis ; apertura parva, cauda brevt. 
Shell small, somewhat conical; apex obtuse ; volutions wide, few, flattened ; costae (7) 
