CERITHIUM. 153 
related to Cerithiwm costellatum, Miinst. (non Deslong.), as that fossil occurs 
in the Upper Lias of Compton, and some of the Bradford-Abbas specimens 
are scarcely to be distinguished from the Lias species, where, however, the cost 
are somewhat straighter—a very unimportant difference. Taken as a whole, with 
all its varieties, this species is eminently characteristic of the Lower Division of 
the Inferior Oolite, but seldom so well preserved or of such large size as in 
Dorsetshire. Though the ornaments are considerably modified by conditions of 
preservation, it may be recognised in a granulato-costate condition in other places, 
as, for instance, in B of Mr. Walford’s Hook Norton section. Cerithiwm vetustwm- 
majus of the Dogger is probably its local representative in the Yorkshire-beds. 
69. CaRITHIUM SUBSCALARIFORME, D’Orb., variety in the Humphriesianus-zone. 
Plate VIII, fig. 9. 
This form is very near to C. subscalariforme as it occurs in the beds of 
Bayeux; it is somewhat smaller, and in the figured specimen the body-whorl 
appears unusually short. The cost also happen to be somewhat more granular 
as in granulato-costatwm, Mist. Occurs in the Sauzei-bed at Oborne. 
70. CeRITHIum suBscALARIForME, D’Orb., variety in the Parkinsoni-zone. Plate 
VIII, figs. 10 a, 10 0. 
Cf. Metanra unDULATA, var. A, Deslongchamps, vol. cit., p. 217, pl. xi, fig. 58. 
Description.—As compared with the previous variety, or varietal group, there can 
be no better description than “testa breviori; costis et striis crassioribus rariori- 
busque.”’ This is a much shorter form, it is more widely angled, and when in the 
granulato-costate condition the spirals are not usually more than four or sometimes, 
in well-developed specimens, five. Corresponding to the greater width of the shell 
the aperture is widely ovate, and it so happens that in the majority of the available 
specimens the anterior canal is by no means distinct (probably the result of wear). 
Relations and Distribution. —This variety possibly represents rather than 
resembles the CO. vetustwm of the Yorkshire-beds. It is essentially a fossil of the 
Upper Division, and is moderately common. ‘The specimen from Grove (fig. 10 a) 
greatly resembles the figure in Deslongchamps’ work (xi, 58), and is exceptionally 
fine. Away from the Dorset-beds the specimens become poorer, worse preserved, 
and may be variously described as O. granulato-costatwm, C. muricato-costatum, and 
even O. vetustum according to local circumstances. 
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