OCR Text |
Show 216 PROF. P. MARTIN DUNCAN ON [Feb. 7, inwards to join the twisted trabeculae of the columella. The septa are marked low down by oblique rows of granules; but there is not a trace of any endotheca. C A R Y O P H Y L L I A C L A V U S , Scacchi, var. T I N C T A. The common British shallow-water coral is represented by a form at Madeira which cannot be separated from it specifically. Indeed it seems to be a simple variety, having a small columella, fewer septa, smaller pali; and the tint of the columella is pearly white, whilst that of the septa and costae is reddish brown. The British variety smithi of Stokes is white, and is found below tide-mark in Devonshire. The corallum is short, with a broad incrusting base, an ephitheca reaching far towards the margin ; there are well-developed granular costae above the epitheca, some projecting, and four complete cycles of septa with some orders of the fifth. The calice is deep, slightly elliptical in outline; and the columella is small, elongate aud narrow, and is formed of a few tall twisted ribbon-shaped processes. The primary septa are exsert; and the secondaries are less so. The pali are small, and are before the third cycle of septa. The granulation of the sides of the septa is in arched rows, one above the other ; and the lateral projection of the granules from the free inner ends of the septa is decided. Length of the calice -| inch. Subdivision CARYOPHYLLIA ENDOTHECATA. Amongst this collection of corals from Madeira is one which, whilst it presents all the characters of the genus Caryophyllia, possesses a distinct endotheca between its septa, occluding more or less the interseptal loculi here and there. It is a most important form, especially when it is considered in relation to Asterosmilia, a genus of Trochocyathaceae or Caryo-phylliae with a double row of pali, and possessing endothecal dissepiments ; for the possession of an endotheca has been considered to be of sufficient classificatory value to place genera with and without it in different families. I propose including the new form amongst the species of Caryophyllia, giving it a subgeneric position. CARYOPHYLLIA ENDOTHECATA, sp. nov. (Plate VIII. figs. 1-4.) The coral is small, with a broad flat base, from which rises a more or less cylindrical body slightly constricted above the base, and narrowed and reentering at the calicular margin somewhat. The calice is circular in outline, rather shallow near the margins, but much deeper at the columella, which consists of four or five distinct nodules. The septa are unequal, well apart, slightly exsert according to the order, and dip down, not reaching the columella. They are thin, slightly wavy in some instances; and the size of the primaries and secondaries distinguishes them. There are four cycles of septa in five systems and in one half of the sixth ; but in |