Among the fossil Cirripedia the species ‘Brachylepas cretacea’ is of extreme interest, since it affords an important connecting link between the pedunculate and sessile forms. Records of its geographical distribution, moreover, show it to have an exceedingly wide range, but up to the present its vertical range appears to be restricted to the zone of Belemnitella mucronata in the Upper Senonian. We owe our knowledge of Brachylepas to Dr. H. Woodward, F.R.S., who in 1868 founded the species B. cretacea on a single valve under the genus Pyrgoma, and in 1901 on a further and more complete specimen established the genus Brachylepas and the family Brachylepadidæ. Attention is now drawn to this species mainly on account of the fortunate find of the remaining valves of the capitulum.