W. H. Hudleston — On the Yorkshire Oolites. 255 



almost identical form is now living, its occurrence in other strata 

 may naturally be expected. 



In Yorkshire Bulla undulata is only from the Cornbrash : it differs 

 very considerably from the fine species of Bulla which occurs in the 

 Coral Rao- of Ayton (see " Corallian Gasteropoda," Geol. Mag. 1881, 

 PL IV. Fig. 6). 



Appendix and Explanation of Table. 



Note as to " Trochis " jugosns, Bean MS. — PI. V. Figs. 11, lla. 

 Shell conical, turrited ; whorls 5 or 6 : suture well marked, and 

 situated in a hollow. The whorls of the spire are angular, and slope 

 outwards to a very prominent carina situate about two-thirds down. 

 Keels sharp and apparently plain. Faint traces of a lower keel 

 may be noted in the whorls of the spire : body-whorl strongly 

 bicarinate. The whole of the shell, including the base, is marked 

 by fine spiral lines. Aperture involved. 



I can hardly believe that this is a Trochus. It has more the look 

 of an Alaria without the wing. On the other hand, it may represent 

 a shell which never had a wing. I would here direct attention to 

 the peculiar fossil called by Deslongchamps Tiirritella unicarinala 

 (Mem. Soc. Linn. Norm. vii. p. 151, pi. xi., fig. 68) said to come from 

 the Oxford Clay of Dives. The author admits its resemblance to 

 " Bostellaria," but has no doubt that it should be referred to 

 TurrifeUa. 



" Trochus " jngosus in Yorkshire is confined to the Dogger, where 

 it is very rare. 



Note as to Nerincea. — I have to thank Mi'. Witchell of Stroud, and 

 Mr. Walford of Banbury, for drawing my attention to some points 

 in connection with this genus, by way of supplement to the remarks 

 made by me in the Geol. Mag. 1884, p. 108, et seq. 



Mr. Witchell writes, " I have never seen JV. cingenda in the Pea 

 Grit, but doubtless Dr. Wright must be correct in putting it in his 

 list. One of the characteristic shells of the Pea Grit in the Stroud 

 area is N. oppelensis, but Dr. Wright has mentioned it as occurring in 

 the Oolite Marl at Selsey Hill. This is an error. For ' Oolite 

 Marl ' read ' Pea Grit.' Your shell, Plate IV. Fig. 8, is, I think, the 

 same species. I have also a Nerincea from Bradford Abbas, and 

 Mr. S. S. Buckman has several examples .... I have not found 

 the genus in any bed lower than the Pea Grit, although I have seen 

 in the cynocephala-zone a spiral shell which may possibly be a 

 Nerincsa." 



Mr. Walford reminds me that the late Mr. Charles Moore 

 described Nerincea liassica, in his Middle and Upper Lias of the 

 S.W. of England. It does not yet seem absolutely certain what this 

 shell really is. I have never seen a specimen myself. Mr. Walford 

 possesses one about 4 mm. in height. 



I may also mention in reference to this subject that none of the 

 so-called Neriiicece, which have been described from the Trias of the 

 Continent, are like typical Nerinceoe. in respect to the columella and 

 disposition of the folds, though such shells may possibly lead up to 

 the more typical forms of the genus. 



