TF. E. Eudkston—On the YorMiire Oolites. 201 



groove it differs entirely from all other forms of Natica occurring 

 in the Inferior Oolite of Yorkshire, where it probably represents 

 D'Orbigny's N. Fictaviensis (Terr. Jurass. p. 191, pi. 289, figs. 8-10). 

 Indeed the Dogger shell is almost intermediate between N. Fictavi- 

 ensis and N. Lorieri {op. cit. p. 190), both of which species are 

 described as being umbilicated and patulous. 



8.— Natica punctura, Bean, 1839. PI. V. Figs. 10a, 106, 11 and 12. 



1839. Littorina punctiira, Bean, Magazine of Natural History, vol. iii. p. 62, fig. 23. 

 1850. Natica pimctura, Bean, Mor. and Lye, Gt. Ool. Moll. p. 112, pi. xv. figs. 18, 



ISffl. 

 1852. "^Natica Sajocensis, D'Orb., T. J. p. 189, pi. 289, figs. 1, 3. 



Bibliography, etc. — The following is the original notice : " Shell 



turbinated, finely striated longitudinally and transversely 



Whorls (6) rounded and well divided, the body-whorl occupying 

 one-half the length of the shell. Aperture elliptical, pillar lip thick 

 and a little flattened, outer lip very thin : length nearly f inch, 

 breadth ^ inch. The only specimen procured from the Cornbrash ; 

 but in the Inferior Oolite at Peak Hill it is not uncommon." 



The type of L. punctura therefore must be sought in the Cornbrash 

 of Scarborough. Morris and Lycett figure a specimen from the 

 Scarborough Limestone ^ (zone 3). Some persons might be disposed 

 to challenge Bean's identification of the Cornbrash and Dogger 

 fossils as belonging to the same species. 



Description, var. Bajocensis, Figs. 10a, 10&. — Specimen from the 

 Dogger (zone 1) Peak (Blue Wyke). Leckenby Collection. 



Length 25-5 mm. 



Width 16-5 ,, 



Eatio of body- whorl to entire shell 60 : 100. 



Spiral angle 65°. 



Shell oval-elongate, not umbilicate. Whorls 6 or 7, increasing 

 regularly ; smooth, turbinated, and rounded off near the suture. 

 Sutural channel distinct, but narrow. Aperture subelliptical, and 

 contracted posteally : inner lip straight. Not the least trace of an 

 umbilicus. 



The surface of the whorls has a sort of punctate structure (see 

 Fig. 10), being the result of decussation of the fine lines of growth 

 with equally fine spiral lines, joroducing a mesh-like appearance. 

 N.B. The specimen is in the condition usual to fossils from this bed 

 (the ^ermcea-bed), viz. shell substance replaced by spathic iron, 

 with skin and lining of brown oxide. 



Type form (Fig. 11). — Specimen from the Cornbrash (zone 4), 

 Scarborough. Leckenby Collection. 



There is no material difference in the proportions of this specimen 

 (selected for the sake of its condition rather than for its size) and 

 that from the Dogger. Owing to the difference in the replacing 

 substance, — the usual waxy-looking calcite of the Cornbrash, — the 

 punctate structure assumes a different aspect. This probably was 

 the aspect which presented itself to Bean. 



^ N.B. Misled by PhUlips's mistake, these authors refer to it as " Bath Oolite." 



