The fossils represented in the accompanying Plate are probably only fragments of the original structure, and possibly only the smaller and less essential portions of the whole. Nevertheless I have determined to publish some account of them, although at the risk of committing an extravagant error, as a last resort towards obtaining more complete examples or suggestions for their more correct interpretation.

Both specimens have been presented to the British Museum; one by J. Wickham Flower, Esq., of Park Hill, Croydon, the other by the Rev. Norman Glass, of London.

The first example (Fig. A) was obtained, at least sixteen years ago, from the Upper Chalk of Higham, near Rochester, and was submitted to Prof. E. Forbes, in whose custody it remained for several years. It was originally shown to me in connection with the anomalous Cirripede Loricula, then newly discovered by Mr. Wetherell. The resemblance between them is certainly curious; but there is no real relationship. Mr. Flower's fossil exhibits distinct traces of the crystalline structure peculiar to the petrified Echinodermata, and the pairs of pores in the ambulacral plates are equally characteristic of the Echinidæ. Mr. Darwin also has examined this fossil and rejected it from his province of inquiry.