8 SUPPLEMENT TO GREAT OOLITE MOLLUSCA. 



Geological Position and Locality. The Great Oolite of Kirklington, Oxon, collected 

 by J. F. Whiteaves, Esq. Eparcy, France. 



GERITHIUM ? STRANGULATUM, Arcldac. Tab. XLIV, fig. 2. 



A shorter and less cylindrical variety of this species was figured in the first part of the 

 ' Great Oolite* Monograph, plate ix, fig. 18. The present specimen, which agrees more 

 nearly with the example figured by D'Archiac, has seven longitudinal costae, which are 

 conspicuous even to the base ; the contracted, pupaeform aperture, with its prominent lips, is 

 alike in both varieties. 



CeritJtium stranyulatum, C. Bulimoides, C. spicitlum, and C. cxiyua, belong to a small 

 group of minute, subcylindrical shells, with prominent, longitudinal costse, and small, 

 thickened, orbicular apertures, which have been referred to Cerithium and to Rissoa ; 

 perhaps eventually it may be deemed proper to separate them under a new generic 

 appellation. 



Geological Position and Locality. The Great Oolite of Minchinhampton Common ; 

 rare. 



CKRITHIUM UNDULATUM (var.), Dcsl., sp. Tab. XLIV, fig. 6. 



MKLAXIA UNDULATA, Deslongchamps. Mem. Soc. Linn, de Normaucl., 18-12, vol. viii, 

 pi. 11, fig. 58, var. a. 



Testa turrita ; anfractibus planis, transversim striatis, ad suturas crenidatis, longitudi- 

 naliter costatis, in ultimo an/radii costis subincurvis, basi obliqua, striata ; apertura 

 elliptica, obliqua, columella maryinata ; labro sinistro fissuram umbilicatem obtit/cnte. 



Var. a, testa breviori, costis et striis crassioribtts, rariorisque. (Deslongchamps.) 



Shell minute, turreted ; volutions flattened, transversely striated, crenulated near to 

 the sutures, and longitudinally costated ; aperture elliptical, oblique. 



Our example constitutes a small and short variety, with narrow volutions (about 8) ; the 

 costa? are large, straight, and from 7 to 8 in a volution ; they are most conspicuous near 

 to their upper extremities, which project, forming a kind of coronary border immediately 

 beneath the suture. Another minute specimen, apparently belonging to the same variety, 

 has the first three volutions almost plain, and the costa? upon the succeeding volutions are 

 but little prominent. 



The typical form of the species figured by M. Deslongchamps has the costa3 much 

 more numerous and less prominent. 



Geological Position and Locality. The Great Oolite of Minchinhampton, collected by 

 E. AVitchell, Esq. 



