Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/543

 rather blunt. Differs from Theca penultima and Theca corrugata in having a smooth surface, and from Theca stiletto in being a larger and wider form, and with a blunt extremity.

Lingulella primaeva, Hicks. Pl. XV. figs. 13, 14.

Half an inch in length and about 1/4 of an inch in width. Some of the valves show a tolerably convex form, and are marked with concentric hues of growth ; most, however, are much compressed and drawn out of form by the cleavage which has affected the beds in which they occur. It is altogether a much larger species than Lingulella ferruginea, which also is found in the same beds. It is moderately plentiful in the red beds at the base of the purple sandstones at Caerfai, Nun's Well, and Porth Clais harbour, on the coast to the south of St. David's ; but as the beds in each case are much cleaved, good specimens are seldom found.

Leperditia ? cambrensis, Hicks. Pl. XV. figs. 15-17.

Valves about 5 of an inch long, by about of an inch in width. Some of the specimens show a reticulated ornamentation entirely distinct from the ordinary lines of growth in a Lingulella, which makes it probable that they belong to the genus Leperditia. In other respects the characters are rather indistinct ; and though specimens are very plentiful in the red beds along with Lingulella primoeva, the cleavage has so affected them that it becomes difficult to recognize their true form, or to note any special characters.

Protospongia? major, Hicks. Pl. XVI. figs. 14-18.

The specimens figured under this name I have possibly incorrectly referred to the genus Protospongia ; but as they approach nearer in character to that genus than to any other yet described from the earlier rocks, I may be pardoned for doing so in preference to making a new genus, where the nature of the fossil is so indistinct. The specimens, however, have very definite characters, and are entirely distinct from those markings so common in the Cambrian rocks, and usually classed together as worm-tracks. In many cases the lines cross each other at sharp angles ; at other times a branching appearance is given ; nearly all appear as if two flattened fibres were joined together longitudinally, one being wider than the other. At present only a few associated beds, almost immediately below those containing Plutonia Sedgwickii, have yielded these fossils ; but in them the markings are very plentiful, covering, indeed, almost the whole surface of the beds. One specimen, however (fig. 18), was discovered by me some time since in the " Menevian group." Fig. 19 represents Protospongia? flabella, Hicks, a Menevian species, but placed here for comparison ; it certainly in some characters resembles Protospongia ? major, and is most likely connected with it generically. Fig. 20 represents P. fenestrata, Salter, also a Menevian species, and the first described of the genus. In this species the

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