On the Affinities of Palceozoic Tahulate Corals. 355 pressa ; apertura latiuscula, brevior quam anfractus ultimus, basi sensim dilatata ; columella brevis, incrassata, baud torta. Long. 1^ mill., diam. |. Hah. Persian Gulf, 14 fathoms {Col. Pelly). Its minuteness constitutes the principal distinctive character of this species. The tubercle which forms the apex is pro-portionally very large.' Planaxis puncto-striatus. B.M. P. testa aciiminato-ovata, nitida, alba, lineis spiralibus riifis, partira interruptis (in anfr. ult. circiter 9), cincta ; spira elongata, apice obtuso ; aufract. 6, parum convex!, primi 3 basimque versus transversim sulcati, caeteri crebre puncto-striati ; apertura ovata, alba, spiram sequans ; columella arcuata cum labro callositate juncta ; labrum incrassatum, intus denticulatum ; canalis basalis brevis. Long. 7| mill., diam. 3^. Hah. Gulf of Suez {M'Andreiv). This pretty species may be recognized from any other by the nine transverse red lines and the punctured striae, about twenty in the body-whorl. XXXVII. — On the Affinities of Palceozoic Tahulate Corals with Existing Species. By A. E. Veerill.* The works of Milne-Edwards and Haime upon corals are so extensive and important, and their classification is so well understood and generally adopted, especially by geologists, that it is of great importance that their errors of classification should be pointed out and fully understood. A very unfortunate mistake was made when they instituted the exceedingly heterogeneous and artificial group known as " Madeeporaria Tabulata." This division was based wholly upon a single character of uncertain value, found in certain corals differing very widely among themselves in all other respects. This character, regarded by them as of such fundamental importance, was merely the existence of complete transverse septa or plates across the coral-tubes, or cells, occu-pied by the lower parts of the bodies of the coral-polyps, thus dividing the lower unoccupied portion of these coral-cells into a series of closed chambers, each plate in turn marking a former position of the base of the polyp which occupied the cell, as it grew upward. In most of the other corals, on the • Communicated by the Author from the ' American Journal of Science ' for March 1872.
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