. Catalogue of the madreporarian corals in the British Museum (Natural History). Scleractinia. PORITES. 13 hitherto there has been no possible means of deciding to which genus they belong. A comparison between the two septal formulse will now enable ns to decide. If the twelve septa conform to Diagram B, then it is a Pontes; if, however, it is an iiiegular reduction of Diagram A, it is a Goniopora. The irregularity is frequently in apparent forkings of the septa before they reach the wall—such a forking as, for instance, we should get if, say, in Diagram A any of the tridents made by
. Catalogue of the madreporarian corals in the British Museum (Natural History). Scleractinia. PORITES. 13 hitherto there has been no possible means of deciding to which genus they belong. A comparison between the two septal formulse will now enable ns to decide. If the twelve septa conform to Diagram B, then it is a Pontes; if, however, it is an iiiegular reduction of Diagram A, it is a Goniopora. The irregularity is frequently in apparent forkings of the septa before they reach the wall—such a forking as, for instance, we should get if, say, in Diagram A any of the tridents made by the 2nd and 3rd cycles lost their middle prongs. The typical septal formula of Porites is that shown in Diagram B, that is, if we omit the rudimentary tertiai'ies inserted in the drawing for the purpose of making the suppression clear. If the reticular theca is regularly built, we can trace two systems of elements in its structure; firstly, the vertical bars, to which the name trabecule is here strictly confined ;* and secondly, the horizontal bars, or horizontal elements or junctions, as they are called in this book. These latter are again diviisible into («) radial bars, original components of the septal plates; and (h) concentric bars, usually called " ;. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original British Museum (Natural History). Dept. of Zoology; Brook, G. L. (George Leslie), 1910-; Bernard, Henry Meyners; Matthai, G. London, Printed by order of the Trustees of the British Museum
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