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Show 438 PROF. P. M. DUNCAN ON DEEP-SEA [May 16, 2. A small, stunted corallum on the same shell as the last, has well-developed calices and costal markings in some places, but, as in no. 1, not everywhere. The calices are of two kinds-those with a large columella made up of several trabeculae forming a more or less globular or circular mass, and those with elongated columellse and well-developed pali. 3. A small trunk on the lower side of the same shell presents calices with a large columella and small pali. The costse are very marked around some calices. These variations in the calicular arrangement in the same corallum and in the same species are very significant, and they prove that the presence or absence of costse, the septal number, the number and dimensions of pali, and the size and development of the columella must not be taken separately to decide specific destinctions if some of the other structures retain their special characters. This coral is a very interesting species, as it is only found off St. Helena; but it, when worn, and when the columella is small, singularly resembles the Synhelia of the chalk. CYATHOHELIA AXILLARIS, Ellis & Solander, sp. This common species, from the Japanese seas, is described in Milne-Edwards and Jules Haime's ' Hist. Nat. des Coral.' vol. ii. p. 110. They omit to state that the pali are situated before the primary, secondary, and tertiary septa, and that in young calices the columella is on a much lower level than the tall papillse of the crown of pali. The thickness of the septa varies according to age. Family ASTR^EID^E. Subfam. ASTR^EINJE. Genus ANTILLIA, Duncan, Quart. Journ. Geol. Soc. 1864, p. 28. A N T I L L T A LONSDALEIA, Duncan, Quart. Journ. Geol. Soc. vol. xx. pl. iii. figs. 4-4c. A variety of this Miocene species which I described from the Tertiaries of San Domingo is found in the Japanese seas at no very great depth. It was sent over by Capt. St. John; and on examining the two specimens I could not distinguish a specific difference between them and the fossil form. The arrangement of the lobed septa, their high cyclical number, their ornamentation and endotheca are most close in their resemblance. The general shape differs a little; and the compressed form of the calice constitutes a variety only. The side view of the corallum is given in Plate XLI. fig. 1, and the details of the calice in Plate XLI. tiff. 2. Division CLADOCORACE^E. D E N D R O C O R A , gen. nov. The corallum is bushy, the ramifications being frequent from all parts, short and frequently forming groups in one plane. The wall is thick except near the calices ; the costse are distinct, and thicker than the septa. The columella is lax and trabecular, having pali |