60 W. S. EucUeston — On the YorlxsMre Oolites. 



larger tlian the angle of the anterior portion of the spire. This 

 coincides with the " apex obtuse " of Morris and Lycett ; hence the 

 shell is somewhat pupoid. 



Description of a Variety. — Specimen from the same horizon, 

 locality, and collection (Fig. 11). 



Length 9 millimetres. 



Width 3-5 ,, 



Angle of anterior portion of spire 20°. 



A shorter and thicker variety, not less pupoid perhaps than Fig. 10, 

 ■which is the most frequent form. There is also a considerable dif- 

 ference in the ornaments. In this one the two uppermost spirals 

 are almost fused into one belt, which is thus strongly bi-tuberculate, 

 and gives a turrited aspect to the whorls in spite of the pupoid out- 

 line of the spire. The third and fifth spirals are faint as in the 

 typical forms : there is no defined system of longitudinals. 



Relations and Distribution. — Cerithium Beanii is clearly a well- 

 marked species, the most prevalent form being that indicated in 

 Fig. 10. The five richly cut spirals, the less pi'ominence of the 

 third and fifth rows, the strong tuberculation of the first and second 

 rows, giving rise to irregular longitudinals sometimes continued to 

 the base of the whorl, are unmistakable characteristics of ornamen- 

 tation. A specimen in the Leckenby Collection, said to come from 

 the Dogger Sands, represents a short and extremely pupoid variety, 

 where thd longitudinals are very thick in the upper part of the 

 whorls. In the specimen thus alluded to the longitudinal almost 

 overpowers the spiral system of ornament — an effect partly produced 

 perhaps by the conditions of mineralization. 



As regards distribution in Yorkshire, C. Beanii, including the two 

 forms. Figs. 10 and 11, is very rare in the Dogger Sands, but rather 

 abundant in the Dogger, especially in the Nerinaia-hed at Blue Wyke, 

 whence both Mr. Herries and Mr. Walford have obtained several 

 characteristic specimens lately. In nearly all cases the apex seems 

 to be missing, nor have I seen any specimen showing a well-pre- 

 served aperture, though, as Cerithium turris (Fig. 13) is a near rela- 

 tive, tlie aperture in 6'. Beanii would probably be not very dissimilar 

 to this one. The presence of C. Beanii on the Millepore horizon, 

 either on the coast or in the Castle Howard district, is not so certain. 

 I rather think that I remember having seen something like it, but 

 do not feel sure. Although I have searched all the collections 

 accessible, there seems to be no trace of it in the Scarborough Lime- 

 stone. Hence C. Beanii in Yorkshire is characteristic of a very low 

 position in the Inferior Oolite. 



Turning to the Midland district, we observe in the Jermyn Street 

 Museum specimens, said to come from the Inferior Oolite of Compton, 

 which have been referred to C. Beanii, and it is quoted in lists of 

 fossils in Judd's Geology of Eutland as occurring in the Lincolnshire 

 Limestone, but not in the Northampton Sand, where we should 

 rather expect to find it.^ No mention is made of this species in Mr. 

 Tawney's list of Dundry fossils, and, as far as I know, it is equally 

 absent from the Bradford Abbas district. 



1 Op. cU. App. p. 281. • 



