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. 



PURPUROIDEA INSIGNIS, Li/c. Tab. XXXI, fig. 2, 2 . 



PURPUEOIDEA INSIGNIS, Lye. Cotteswold Hills Handbook, &c., pi. 7, fig. 8, a, b. 



Testa turbinata, ovata, injlata, spira cxserta, anfractibus 5 subangulatis, tuber cults 

 depressis (9 in anibitit), anfractii ultimo magno inflato, plerumqiie sine tuberculis ; ajwturd 

 magnd 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. nodttlata, 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. Scllona, 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 

 ' Paleontologie Frangaise,' as Ornata, Bianor, Bixa, and Batltis, have, together with a 

 thin shell, a lengthened, subulate figure and an entire aperture ; these should be placed with 

 the Littorinida?, and should range by the side of Amberleya, figured and described in the 

 first part of this monograph. I am inclined to claim for Amberleya 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. 



CERITHIUM BATHONICUM, Lye. Tab. XLIV, fig. 19. 



Testa parva subconica, apice obtuso, anfractibus lutis, paucis, plants ; costis (7) rectis 

 magnis, oblusis, striisque cingcndis ; apertura parva, cauda brevi. 



Shell small, somewhat conical ; apex obtuse ; volutions wide, few, flattened ; costae (7) 



