. W. H. Hudleston — On the Yorkshire Oolites. 59 



Confined in Yorkshire, as far as I know, to the more marly beds 

 of the Scarborough Limestone, C. gemmatum is moderately plentiful 

 in the grey marly Oolite of White Nab, whence Mr. Berries obtained 

 specimens lately. Under what synonym it lurks in other localities, 

 or on other horizons, I have not yet discovered, supposing it to be 

 anything more than a local form.' It would be almost too hazardous 

 to suggest that C. granidato-costatum partly represents it. 



25. — Cerithium Beanii, Morris and Lycett, 1850. Plate III. 

 Figs. 10 and 11. 



18o0. Cerithium Beanii, Morris and Lycett, Grreat Ool. Moll. p. 112, pi. xv. fig. 5. 

 1875. Ibid. Ibid., Phillips, 3rd edition, p. 257. 



Bibliography, etc. — This species was originally described by the 

 authors of the Great Oolite Mollusca as occurring " near Scar- 

 borough," and therefore presumably either in the Millepore Kock 

 (zone 2), or in the Scarborough Limestone (zone 3) — at that time 

 supposed to represent the Great Oolite. I have not succeeded in 

 identifying the type specimen (which is but poorly figured) in any 

 of the collections, nor have I seen any specimens in the matrix 

 of the Scarborough Limestone anywhere. For this reason I am 

 forced to the conclusion that Phillips in his third edition has made 

 a mistake (p. 257) in confining this species to his " Grey Oolite," 

 i.e., to the Scarborough Limestone. All specimens seen, by me, no 

 matter in what collection, are unmistakably from the Dogger, 

 though there are dwarfed forms in the Millepore Eock which might 

 represent it. In the Scarborough Limestone even these do not occur, 

 if I maj' judge by the collections or by my own experience. 

 Notwithstanding the prevalent impression to the contrary, C. Beanii, 

 in all its varieties, is essentially a shell of the Dogger. 



The following is the original diagnosis. " Shell small, turrited : 

 apex obtuse, volutions numerous, narrow, rather flattened, encircled 

 with five rows of costse : costas tubei'culated, the costse being about 

 16 in a volution : ribs unequal, sutures of the whorls deeply de- 

 pressed ; third and fifth row of costaj less prominent." 



Description. — Specimen from the Dogger (zone 1), Peak (Blue 

 Wyke). York Museum (Fig. 10). 



Lengtli from base to apex about 12 millimetres. 



Width 3f „ 



Hei-ht of whorl to width 2 : 3|. 



Spiral angle of apex probably about 25°. 



Ditto of anterior portion of spire 16°. 



This specimen corresponds so well to the above diagnosis of the 

 species that there is very little to add. The upper row of spirals is 

 strongly tuberculated, and so contributes to the turrited character 

 of the shell. There is no proper system of longitudinals, but an 

 irregular development in the upper part of each whorl, where the 

 nodes or granulations have a tendency to become confluent in an 

 axial direction. The apex, in this specimen, is broken off, but it 

 seems clear that the opening of the spiral angle was considerably 



^ Quoted as common in the Lincolnshii-e Limestone, App. to Judd's Geol. of 

 Eutland, p. 281. 



