W. H. Hudleston—The Yorkshire Oolite. 401 
Shell short, conical, smooth, not umbilicated. The whorls are five 
or six in number, convex, and have a tendency to increase under a 
high angle with a nearly uniform slope and but little tabulation. 
Body-whorl considerably higher than the rest of the spire and mo- 
derately ventricose. The condition of the specimen does not admit 
of a more detailed description. 
Relations, etc.—This is unfortunately the only specimen I can 
obtain. It is one of the very few Univalves of the lower beds, and 
a more exact determination would therefore be desirable. Some 
might regard it as a small Natica, like N. punctura, Bean, for instance. 
To me the shell appears too evenly conical for a Natica, and though 
so small it very much resembles specimens from Minchinhampton 
referred as above. 
Genus Cerrruium, Adanson, 1757. 
There are no more than three species which can be said to be com- 
mon, viz. C. muricatum, Sow., C. limeforme, Roem., and C. inornatum, 
Buv., as identified. The number of the remainder would vary accord- 
ing to the views taken respecting varieties, but under any circum- 
stances seven or eight would be the limit. This is about the number 
given by Morris and Lycett for the Great Oolite Cerithia, but the 
species in that formation are for the most part very different to those 
of the Yorkshire Corallian. 
In Germany, according to the older authors on the Jurassic rocks, 
the muricated Cerithia are represented by C. costellatum,' Miinst., Lias; 
C. muricato-costatum, Miinst., Lower Oolites; C. nodoso-costatum, 
Miinst.; C. septemplicatum, Roemer, Upper Coral Rag. The granu- 
lated forms are C. quadricinctum, Mimst., Lower Oolites, and C. 
limeforme, Roemer, Upper Coral Rag. Since those days Buvignier ? 
has described and most elaborately figured twenty-nine species of 
Cerithia, of which fourteen are from the Coral Rag of the Meuse, 
with one exception, all being claimed by him as new. 
De Loriol and Pellat* also have made a handsome addition to the 
lists in respect of this genus, and several of their new species are of 
Corallian age. Some indeed look like old friends we have seen 
before under other denominations. 
17.—CrritHium murricatum, Sow., 1825. Pl. XIV. Fig. 7. 
Turritella muricata, Sowerby, 1825, Min. Conch. vol. v. p. 159, pl. 499, figs. 1 and 2. 
Ibid, 1829, Phillips’s Geol. of Yorkshire, t. 4, fig. 8. 
Cerithium Struckmanni, Loriol, 1873, Et. Supr. Jurass. vol. i, p. 75, pl. vii. figs. 
25-27. 
Bibliography, ete.—Sowerby’s original specimens are from Steeple 
Ashton. His fig. 1 is a characteristic block full of this very common 
form, along with the well-known “ Turbo” muricatus. Fig. 2 is a 
good representation of a single specimen of the type which is so 
plentiful in the shell-beds of the Coralline Oolite of the southern 
counties. Being excessively common, and having probably a great 
range, this shell has naturally attracted the attention of many writers 
1 See Goldfuss, Petrefacta, div. v. p. 29, pl. 143. 
2 Stat. Géol. de la Meuse. 3 Et. Supr. Jurass. de Boulogne. 
DECADE II.— VOL. VII.—NO. IX. 26 
