W. H. Hudleston — On the YorJcshire Oolites. 201 



Shell elongated, turrited. The spire probably consisted of about 

 14 whorls ; eight now remain ; of these the anterior ones are in a 

 good state of preservation. They are separated by a wide and 

 tolerably deep suture ; the upper part of each whorl is constricted, 

 the middle nearly flat, and the lower very shai'ply constricted, the 

 effect being to produce a tumid whorl, flattened towards the middle, 

 but curving towards either suture, the posterior curved area being 

 longer than the anterior one. 



The whole shell is ornamented with prominent spiral bands, which, 

 on the penult, are distributed as follows: — (1) In the upper part, 

 close to the suture, a narrow and not very conspicuous band, followed 

 by an immediate increase in the convexity ; then a broad conspicuous 

 band, a wide sulcus which includes a faint spiral line, another spiral 

 band, and then a second sulcus which contains a spiral line some- 

 what stronger than the preceding one. (2) The middle part is 

 composed of three nearly equal strap-like bands, the upper being 

 slightly the strongest and representing the most angular portion of 

 the otherwise globose whorl ; these seem to have undergone a certain 

 amount of polishing. (3) The anterior region, which is the shortest 

 and most sharply constricted, contains two bands separated by a 

 sulcus, in the bottom of which is a faint spiral line. There are no 

 traces of a longitudinal system of ornament, beyond a general ap- 

 pearance of fine vertical strise, which have the effect of producing 

 a slight ornamentation of the spiral band. This may extend to the 

 sulci, but it is not certain that it does so as represented in Fig. 8. 



The base of the shell is ornamented by a similar system of spiral 

 bands. The columella is short and straight, and the aperture appears 

 to have been entire and rounded ; but a small portion of the anterior 

 margin is wanting, and the outer lij) is partly involved in matrix. 



Another Specimen. Section B. — Same horizon and locality. 

 Leckenby Collection. Figs. 10, 10a. 



Length restored about 30 millimetres. 



. Height of whorl to width 60:100. 



Spu'al angle towards the apex about 20°. 



Contains more of the . apical whorls than the preceding ; ten 

 remain, and about 3 or 4 more would be necessary to complete the 

 spii'e ; the body-whorl is smashed. There is an irregularity about 

 this fossil which may be due to compression of the lower part. The 

 apical whorls are short, globose, and separated by a large suture, 

 which has the effect of giving a strangulated aspect to this part of 

 the spire ; three are ornamented by numerous fine spiral lines. 

 Presently the whorls assume an outline which is slightly more 

 angular, and the spiral banding is more distinct. Their general 

 character is similar to those in the preceding specimen, but with 

 certain important differences. The bands are broader and more 

 strap-like, and the sulci limited correspondingly. 



If these peculiarities can be explained as the result of usage, then 

 we could agree to refer both A and B to the same section of the 

 opalina group. B (Fig. 10) has considerably more resemblance to 

 Quenstedt's figure than has A (Fig. 9). But if we cannot allow 



