Both on account of their beauty and extreme rarity, and of the important part they have borne in the fauna of some of the past periods of the earth’s history, the first order of the Echinoderms, the Crinoidea, has always had a special interest to naturalists; and, on the watch as we were for missing links which might connect the present with the past, we eagerly welcomed any indication of their presence. Crinoids were very abundant in the seas of the Silurian period. But during the lapse of ages the whole order seems to have been worsted in the “struggle for life.” They become scarce in the newer Mesozoic beds, still scarcer in the Tertiaries, and up to within the last few years only two living stalked crinoids were known in the seas of the present period, and these appeared to be confined to deep water in the seas of the Antilles, whence fishermen from time to time bring up mutilated specimens on their lines. Their existence has been known for more than a century; but although many eyes have been watching for them, until very lately not more than twenty specimens had reached Europe, and of these only two showed all the joints and plates of the skeleton, and the soft parts were lost in all. These two species belong to the genus Pentacrinus, which is well represented in the beds of the lias and oolite, and sparingly in the white chalk; and are named respectively Pentacrinus asteria, L., and P. mülleri, Oersted. The first of these has been known in Europe since the year 1755, when a specimen was brought to Paris from the island of Martinique, and described by Guettard in the Memoirs of the Royal Academy of Sciences. For the next hundred years an example turned up now and then from the Antilles.