32 MADEEPORARIA, 



same group as P. Porto Rico 3, P. West Indies x. 18, 19 and 20, only it is not so compact, the 

 forking being at slightly larger angles. 



The sinuous stems forming the cluster bend up more slowly and with a more open curve ; the 

 bends are thus more conspicuous, and the swelling of the stems is much more gradual, and is 

 chiefly to be seen in tlie fact that the original stem supporting the whole stock is under 1 cm. 

 thick, while some of the top stems are nearer 1*5 cm. The small base from which the stock 

 rises is interesting, cf. P. Barbados 10, and the observation thereon. 



The fact cannot be overlooked that this is called by Dr. Vaughan Porites porites, as if it 

 were the type of the ideal species of branching forms in the West Indies, that is, the type 

 of which all the others aie hut formm, forma clavaria, seep. Q3, forma furcata, seep. 64, /orma 

 divaricata, p. 62. As I have already shown at length in the Introduction, there is no justification 

 for this in the history and still less in the morphology of the group. In growth-form, 

 this coral shows a transition between a simpler type of growth with regular dichotomous 

 branching and straight prongs and the type in which the prongs all bend upwards and inwards 

 to form a close cluster of sinuous stems gradually thickening as they rise, as in Dr. Vaughan's 

 ov/n forma clavaria, see p. 63. 



There is no trace of resemblance between this growth-form and that of Seba's coral, the 

 figure of wliich is given on PI. XVII., fig. 3. The two show quite opposite specialisations, the 

 latter has the prongs flung, as it were, outwards in all directions, the very reverse being the 

 case in this coral. 



9. Porites Curagoa 3. (P. Curofoce tertia.) (PI. IX. fig. 6.) 



[Paris.*] 



Description. — The corallum seems to rise on a short thick stem, 1"25 cm. in diameter, 

 which soon forks into an irregular candelabra-like cluster of short, thick, upcurving branches, 

 the tops of which fork again irregularly into short, round or flat-topped terminals. These may 

 be as thick as the original stem of the stock. The living layer extends 5 cm. deep. 



The calicles are large, 1 • 5 mm. in diameter, angular and everywhere sunk ; at the tips 

 they are deep. The walls are sharp and distinct, with a fine wall-thread, often zigzag. The 

 septa are well developed, thick, slightly and irregularly echinulate ; they descend as lamellate 

 plates with deep interseptal loculi ; here and there in the base of the calicle they can be seen 

 joining the paU. These latter are tall, stout, smooth rods, 5 to 6 in number, but not con- 

 spicuous to the naked eye. The columellar tangle is obscure, but the central tubercle is 

 very small and flattened. The general aspect of the calicles to the naked eye is not unlike 

 that characteristic of the astraeoid group (see p. 142) ; in this fact the coral is remarkable 

 among branching forms. 



The colour of the unbleached coral is a reddish buff. 



This form is of interest, because it shows another branching Porites from Curaf oa, quite 

 different from either Seba's or Dr. Vaughan's specimens, see P. Cura^oa 1 and 2. The growth- 



• This specimen is labelled " J, Bavea, pr6s de Cura9oa." I presume that the first words refer 

 to the collector's name, as I can find no name " Bavea " on any of the available map.s or charts of 

 Cura9oa, 



