W. H. Hudieston—The Yorkshire Oolite. 297 
the condition of casts, the comparison is not easy. The resemblance 
to the smaller shell (Fig. 4) is sufficient to connect it with N. arguta, 
and there is the further fact that the specimen (the property of the 
Yorkshire Philosophical Society) has been so labelled in their 
Museum. 
It is a very marked species, totally different from any of the three 
previously described, and, as it requires a name, there can be no 
harm in assuming that Natica arguta will fit it. The other specimen 
(Fig. 5), though so much larger, can hardly be separated. 
Description of Fig. 4.—Specimen from the Corallian of Yorkshire 
(Yorksh. Phil. Soc.). 
Mens thy (mestoredyy sii ie caste «cies © sk wiaretelsleccl« 37 millimétres. 
Wiidtby (restored) (Ga%)o cette erstees tale ate wre 23 Ay 
Length of body-whorl to entire shell ........ 58 : 100. 
Mp aeMRH RENDER A are gee GA It ach) cal “leaatat een wise tyetie 61°. 
The state of preservation is not favourable to accurate description, 
as the substance of the shell is partly dissolved away, yet the general 
contour cannot be mistaken. Shell ovate oblong, much longer than 
wide; whorls five or six in number, smooth, rounded, without any 
flattening of the upper portion, which is rounded off, and then falls 
away steeply towards the base of the whorl. Outer lip imperfectly 
preserved; the inner lip shows a moderate callosity, and there is a 
faint trace of an umbilicus, exposed perhaps owing to the partial 
wearing away of the inner lip. The character of the aperture, and 
indeed of the whole shell, is rather like that of the so-called 
Phasianelle of the Oolites. 
Fig. 5.—Specimen from the Coral Rag (?) of Slingsby (Leckenby 
Collection). 
Merete (restored oe. « sfocdicicnde ove ctadsae 53 millimetres. 
WWaidltthi® (restioned)\itie Sy caver tects) ots cn fer elvyeto ere oti, Nae 
Length of body-whorl to entire shell ........ 61: 100. 
Ppiralwancle: acs gsc ctshory ol atene acer arelclos,shshe 62°. 
This specimen is in a similar mineral condition to the one just 
described, the surface of the shell being much thinned away. 
Though so much larger, the proportions are nearly the same, and, 
except as to size, the description of one will serve for the other. 
There is at first sight some apparent difference in the contour of the 
outer lip, but this is probably due to unequal preservation of their 
respective margins, the larger shell having been broken away con- 
siderably anteriorly, so that this part of the aperture appears less 
elliptical. 
Relations and Distribution—As the larger specimen is, as far as I 
know, unique, I shall merely view it as a megalomorph of the form 
identified as Natica arguta (Fig. 4). In the Great Oolite of Minchin- 
hampton, whose Naticas, as we have seen, so closely resemble those 
of the Coral Rag of Yorkshire, there is nothing with which it can be 
compared, nor have I yet noticed the form in the Corallian of the 
South of England, except as a fragment in the Natica bed at the top 
of the Lower Cale Grit near Cumnor. However, Natica arguta is 
quoted by Whiteaves from the Corallian of Oxford. 
