W. H. HucUeston — On the Torkshire Oolites. 203 



The complete spire consisted of from 10 to 12 wliorls: 8 are 

 visible, though the 5 anterior ones alone preserve their ornaments. 

 Whorls plano-convex, and slightly angular, sutural excavations 

 very wide, with a faintly-marked rim in the centre, constituting the 

 base of each whorl. These are further ornamented by 4 deeply 

 granulated spiral bands, the granules are slightly drawn out spirally : 

 the third row the strongest, fourth row almost smooth. In the body- 

 whorl the raised line, previously noted in the sutures, occupies the 

 edge of the shell, beneath which the base is rather flat and orna- 

 mented with numerous spiral lines. Indications of longitudinal 

 strice faint. 



There is nothing about the aperture to indicate that the specimen 

 is a CeritJiium ; still the state of preservation is not favourable to 

 accurate description. 



Another specimen. Dogger Sands (lower part of zone 1), Blue 

 Wyke. Leckenby Collection. Fig. 12, magnified twice. 



Dimensions nearly the same as in the preceding, and the ornaments, 

 where visible, identical. The sutural hollow is more filled up with 

 matrix, and the ornaments partially obscured from a similar cause. 

 The aperture is almost perfectly circular, although there is a slight 

 in'dentation in the anterior margin — a mere irregularity, as I believe, 

 owing to the ^v'litj nature of the matrix. 



Relations and Distribution. — This form represents a wide-angled 

 variety of a group of Turritellce with four strongly marked spirals 

 on the whorls. If we are to regard it as distinct from the next 

 "species" (Fig, 13), it is rare, though occurring both in the Dogger 

 and the Dogger Sands. 



48.— TrKRiTELLA. riate VII. Figs. 13, 13a. 

 . Description. — Specimen ftom the Dogger (zone 1), Peak (Blue 

 Wyke). Leckenby Collection. 



Length 13 millimetres. 



Spiral angle 20°, 



Except in its being more slender, and perhaps with a less wide 

 suture, there does not seem much difference between this variety and 

 the typical T. quadrivittata, which it serves to connect with such 

 a species as T. eucycla, H. & D. (op. cit. p. 47, pi. i. fig. 11), a yet 

 more slender form occurring in the Callovian of Montreuil Bellay. 



This also is rare, but Mr. Walford obtained a specimen very 

 similar to the one now figured during a recent visit to the Dogger. 



EXPLANATIOJSr OF PLATE VII. 



Fig. 1, la. Alaria trifida, Phillips. Kelloway Eock, Scarborough. Leckenby 



Collection. Back view and body-whorl enlarged. 

 ,, 2, Alaria trifida, Phillips, Oxford Clay, Scarborough. Leckenby 



Collection. Back view. 

 ,, 3, Za. Alaria trifida, Phillips. Kelloway Eock, Scarborough. Leckenby 



Collection. I'ront view and whorl enlarged. 

 ,, 4, 4a. Alaria inyurus, Deslongch., var. teres. Cornbrash, Scarborough. 



Leckenby Collection, Back view, and body-whorl 



enlarged, 

 ,, 5, 5a. Alaria, sp. Dogger, Blue "Wyke. Leckenby Collection. Back view 



and body -whorl enlarged. 



