W. H. Hudleston—The Yorkshire Oolite. 397 
Oolite at Scarborough (Scarborough Limestone), and this was 
referred by Morris and Lycett (p. 118, pl. xv. fig. 19) to Sowerby’s 
species. Some of the specimens from the Cheltenham district are 
marked Ph. Semanni, Oppel, and P. Oppeli, Wright MS., in the 
Jermyn Street Museum. Young and Bird, edition of 1822, give a 
very recognizable figure (pl. xi. fig. 9) of one of the more obese 
forms, and D’Orbigny’s figures (Ter. Jurass., plates 324 and 325) 
are excellent. The latter: author (op. ett. vol. li. p. 323) speaks of 
the species as occurring on two stages—in the Callovian at Pizieu, 
and in the Oxfordian at many places both in France and England. 
From this fact we may infer that D’Orbigny’s Oxfordian must include 
much of our Corallian. 
Description. Fig. 1a. Specimen (cast) from the Coralline Oolite of 
Ness (my Collection). The spiral angle rather exceeds 40° 
(D’Orbigny’s limit is 30°—44°). The whorls, five in number, increase 
under a regular angle, and are tumid above, but become more 
depressed below. The last whorl rather exceeds the whole of the spire 
in height, and exhibits on a larger scale the characters of the other 
whorls; it is not either rounded off or bevelled off, but presents an 
angular outline, which is characteristic of all stages of the species, 
though it is lost in old and very large specimens. The cast is too 
much worn to show the usual traces of the thin striated shell. 
Fig. 1b.—Specimen from the Corallian of Yorkshire (Leckenby 
Collection.) 
Mieripetn (Pest ONE) jin 5 sin bison s<ualarws ewaleila hep» 28 millimétres. 
PR ao jels ain mae toy cas estaba ope) na es nase apie are LOS iiss 
Length of last whorl to entire shell .......... 50: 100 
BINT UU HAIER ove w/a ciclnie aivinrs napeouts cin mares ee 42°. 
The shell of this specimen, which may be taken to represent the 
next size of the ordinary form of Ph. striata, has its lower whorls 
preserved in calcite. 
The whorls of the spire are tumid, and the shell substance thick, 
the transverse banding characteristic of the species appearing on the 
surface somewhat faintly. The body-whorl is also tumid, but not 
disproportionately : its shell substance would seem to have been less 
thick, and the transverse banding shows out better where the shell 
is thinner. It is probable that the banded structure pervades the 
entire thickness of the shell, as it is so well shown upon casts. The 
bands in the base of the body-whorl are wider and more prominent. 
Relations and Distribution. — As previously indicated, opinions 
differ as to whether this great shell is really the same as the one in 
the Inferior Oolite. It is, or its closely allied congeners are, amazingly 
abundant on certain horizons in the Jurassic rocks, whilst totally 
absent from others. Thus there is no representative of the group in 
the Great Oolite of Minchinhampton, where there are so many 
Gasteropods, nor yet in the Cornbrash of Yorkshire. It is 
immensely abundant on certain lines in the Yorkshire Corallian 
beds, not so low, however, as the Lower Coral Rag of Hackness. 
Very large specimens occur in the shelly beds which succeed the 
Middle Calcareous Grit in parts of the Tabular Range, and it is 
