Fossils in the red Cambrian rocks are so rare, that no apology seems due for introducing a single small specimen, lately gathered, after great research, by one of the authors of this paper. The search has been systematically pursued since 1862, when the first fossil of the Menevian group was described by Mr. Salter from this neighbourhood; and the labour has chiefly fallen upon Mr. Hicks, who resides at St. Davids. He has literally not left a stone unturned to find the true place of Oldhamia, and, if possible, of the mythical Palæopyge, in these old red rocks. He has been rewarded, during the search, by many additions to the Menevian fossils, found at successively lower and lower horizons, in the grey rocks which form the passage from the Lower to the Upper Cambrians. But, until quite lately, not a vestige had occurred to him in the actual red rocks themselves.