On a new Species of Cyphaspis from the Carboniferous Rocks of Yorkshire

Abstract

During the visit of Prof. Hughes's geological party to the Craven district in June last, I was fortunate enough to find in the Pendleside limestone at the base of Butterhaw, near Cracoe, a fairly perfect head of a Trilobite which appears to belong to the genus Cyphaspis . Hitherto this genus has not been recorded above the Devonian, and its discovery in rocks of Carboniferous age seems worthy of notice. Description .—Head small, semicircular, very convex, 3"5 millim. in length and 5 millim, in width. Frontal border broad, flattened,minutely granulate. Its margin produced into a number of equidistant,horizontal, cylindrical spines, -5 millim, long. In our specimen they are visible on the righ~ antero-lateral portion of the border, and one near the left genal angle. They are -4 millim. apart from each other, and as the frontal border is 9-6 millim, in length, there must have been 24 spines present. Genal angles invisible, probably prolonged into short spines. Glabella very prominent, ovoid, narrow behind, afd widening gradually for four fifths of its length. Slightly constricted at the two glabella-filrrows on each side, much raised above the cheeks; covered with small granules and bearing four tubercles, a pair near the upper part of the anterior sloping surface, a large unpaired 6no near the centre, and a smaller median one behind. Of the glabella-furrows the anterior one is short and, seen from the side, is directed backwards, while looked at from above it appears as a pit in the axal furrow,marking off an imperfectly defined