54 W. S. Iludleston — On the Torkshire Oolites. 



be regarded as identical in form and ornaments with Fig. 2, due 

 allowance being made for difference of matrix. 



Fig. 3. — C. muricatum, var. sexlineatum. Specimen from the Dogger 

 Sands (lower part of zone 1), Blue W^'ke. Leckenby Collection. 



Length (restored) 22 millimetres. 



Width 6i ,, 



Height of whorl to width 3-o : 5. 



Spiral angle 18°. 



Spirals 6 in number ; the nodes at the intersections are much 

 drawn out spirally, so as to produce a slightly different pattern, 

 which is somewhat exaggerated in the figure. Longitudials con- 

 siderably' curved ; nodes fine and sharp, as though originally rather 

 more spinous. 



Whilst Figs. 1 and 2 represent comparatively common forms, 

 Fig. 3 represents the only specimen I have seen. Such a specimen, 

 if regarded simply by itself, might well be deemed to belong to a 

 distinct species. 



Fig. 4. — Specimen from the Cornbrash (zone 4), Scarborough. 

 Leckenby Collection. 



Length (restored) 23 millimetres. 



Width 6i „ 



Spiral angle 16°. 



Spirals 4 in number, nodes but little drawn out spirally, and not 

 in the least echinate ; longitudinals moderately curved — more so 

 than is shown in the figure. Suture wide, upper spiral band of each 

 whorl but little prominent. In this specimen the aperture is well 

 preserved ; its subquadrate character and anterior canal being well 

 seen. A small oyster causes a thickening on the end of the canal. 



The striking peculiarities of Figure 4 are perhaps as much due to 

 status as to any other cause ; the ornaments appear to have been 

 rounded by a sort of polishing action, which may be partly chemical, 

 partly mechanical. The older authors in making species do not 

 seem to have had any regard to the external changes thus produced 

 by fossilization. What we are certain of in this case is that the shell 

 was spirally quadrilineate with curved longitudinals. It may be 

 near to a Cerithivm, stated by Morris and Lycett (Great Ool. Moll, 

 p. 29) to be the most common of the genus in the Great Oolite of 

 the Cotteswolds, and which they refer to C. quadricinctum, Mtinst. ;' 

 but, after all, this is no more than a conjecture as regards the Scar- 

 borough fossil. On the other hand, some might prefer to compare 

 it with C. granulato-costatum, Miinst., only it happens to have 

 4 spirals instead of 5, and is hardly at all turrited. 



Fig. 5. — Cerithium Culleni, Leck.^ Type Eefigueed, Specimen 

 from the Kelloway Eock (zone 5), Scarborough, Leckenby Coll, 



Length (restored) 13 millimetres. 



Width 3^ „ 



Spiral angle ?13°. 



1 Goldf. Gast. p. 30, pi. 173, fig. 11. 



2 Q. J. G. S., vol. for 1859, p. 13, pi. 3, fig. 13. 



