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Show 748 MR. J. STANLEY GARDINER oN [June 6, Milne-Edwards and Haime are almost certainly varieties of previously described species, due to position of growth. It is noticeable that there are in the collection no two specimens exactly alike in their calices, no two, indeed, which do not give as good specific differences as many of the species described by Milne-Edwards and Haime. Indeed without drawings (or preferably photo-plates) descriptions are absolutely useless. I have described one specimen as new; it differs markedly, in the characters of its septa, in its distinct calicular rim (formed by the theca), and in the deep sulci, from all previously described species. 1. ASTRCEA DENTICULATA Ellis & Solander. (Plate XLVII. fig. 1 ) Madrepora denticulata, Ellis & Solander, Zooph. p. 166, pl. xiv. fig. 1 (1786). Favia denticulata, Milne-Edwards & Haime, Cor.ii. p. 428(1857). There are two specimens of this well-known species, which is very common on the lagoon reefs and on the outer reefs to leeward at Funafuti. The thecae of neighbouring calices are generally completely fused, forming thin dividing walls. In places, however, the thecae are distinct at the surface and about 1 m m . distant one from another. In the more vigorously growing portions of the colonies the calices are deep, the septa slope directly down to the axial fossa without any distinct paliform lobes, and the columella is very small and inconspicuous. On the. undersides and least vigorously growing portions of the colonies the calices are shallow, the septa have broad, paliform lobes, and the columella is a distinct trabeculated mass. Funafuti; lagoon and outer reefs. 2. ASTRJEA FRAGILIS Dana. Astrcea fragilis, Dana, Zooph. p. 230, pl. xii. fig. 2 (1848^ Two specimens, which agree closely with Dana's figures and description. The larger calices are about 9 m m . in breadth by 4-5 m m . in depth. Their dividing walls are 1-1*5 m m . broad and compact. The septa form three complete orders, the fourth beino* represented by about 6 septa. The primaries and secondaries are subequal and slightly thicker, broader and more exsert than the tertiaries. The septa are not usually continuous between the calices over the walls, which accordingly show commonly a distinct sulcus. In the Rotuma specimen the septa are thicker and more exsert, and the wall has a more distinct sulcus than in the Funafuti specimen, in which further the septa of the first three orders approach one another in size. The columella is generally distinct, being formed by very fine spongy trabeculae. Funafuti; lagoon. Rotuma; boat-channel. 3. ASTRcEA PALLIDA Dana. Astro^apallida, Dana, Zooph. p. 224, pl. x. fig. 13(1848). Two specimens, corresponding closely to Dana's description and figures (except fig. 136, " cells in outline") and having living |
