Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/245

Rh J. S. GARDNER ON BRITISH CRETACEOUS PATELLID.E ETC. 197

range on the Continent as it has in England. Many specimens have been found at Atherfield, others at Pedcliffe, Isle of Wight, Devizes, East Shalford, Sevenoaks, Seend, Donnington, Speeton, furze Hill, Parringdon, &c.

Stoliczka, in the i Pal. Indica/ remarks that the farrow in Sub- emarginula, Blainv., is lateral, and that this and the other species possessing the lateral emargination might form a subgenus. The character, however, is seen in this species to be inconstant.

Emarginula valanglensis, Pict. & Camp. Lower Greensand. PI. VIII. figs. 7-9.

The species is described by Pictet and Campiche as being some- what quadrilateral, and possessing 26 ribs, with intermediate strice, only the accessory ribs of E. neocomiensis being absent. The form of the scar on the cast figured by them differs from that of the species last described. Mr. Meyer has found specimens at East Shalford which may probably belong to this species, but which are unfortu- nately too imperfect to determine with any degree of certainty.

Emarginula puncterella, sp. nov. Lower Greensand. PI. VIII. figs. 10, 11.

Shell minute, oval, cap-shaped, elevated, compressed laterally ; apex sharp, recurved, overhanging posterior margin ; sculpture, 30 strong ribs, cancellated by transverse Hues ; each interspace possess- ing two pits, arranged horizontally in pairs.

The cast shows a fissure extending about - the height of the shell, leaving a deep, sulcated scar on the remainder. This scar possesses an elevated median region, with strong imbrications re- sembling the teeth on a cog-wheel (fig. 11 b). The dimensions are, 1. 7 millims., b. 5 millims., ht. 4 millims.

This species very much resembles E. neocomiensis ; and the pits on the cast might be supposed to represent, in but a very slightly mo- dified manner, the more quadrate interspaces between the ribs and strias of that species. The shell, however, is higher and more com- pressed, the fissure is relatively longer, and the scar approaches much nearer to the apex. It appears to present certain affinities with Rimula.

The specimens figured are selected from several found Ly Mr. Meyer at East Shalford, and represent the shell natural size and magnified ; the ornamentation being drawn from a cast, is shown in elevation instead of depression.

EiiARGiNULA Gresslyi, Pict. and Camp. Upper Greensand to Grey Chalk. PL VIII. figs. 12, 13, 1(3-18.

Shell ovate, or rounded, rather depressed ; apex subcentral or | posterior, slightly recurved ; sculpture, about 200 fine ribs, crossed by still finer transverse lines, and marked also by lines of growth. The reticulations, which are very delicate, have no nodes at the intersections. The fissure is long, extending one fourth or more between margin and apex, and leaving on the rest of the distance a raised, ridge-like scar, which is sometimes depressed centrally.