is more marked than in the Upper beds but all show some alteration. Near the Lead of Aber Dyfrdwy we had the men over across from the Ordovician shore, theday across to the eastern side. The distance may have been 1300 feet and here we came at once upon the Lower Cambrian metamorphosed shale interbedded with thin bands of quartzite. This is Rickardson's C9 and is 68 feet thick. They strike N-5, dip 28 deg. At about the middle of this zone, but found as loose pieces along the shore, I got slate jaws of a thick but very short Sallterella. Below the shale comes zone C8 that at the top is a grey to light blue limestone composed of small comminuted fossil material. In the little while collected during a rain we got Ptychus, Paternula and Platyceras primacera. Drilling thrust our work by in tomorrow. The next day we collected again more. The common fossils are Ptychus, Sallterella and Deltellus. Deltellus are rare. Of Platyceras primacera we have at least four. There are probably a few more species not listed here. Most of this material came from the base of C8 but the Platyceras came from near the top. Zone C8 has a thickness of 13 feet and is almost as described by Rickardson.