1899.] conAUjUBJE of madeira. 59 



The spicula of the cortex comprise three forms : — (1) Spicules 

 shaped like an opera-glass or like two carafes joined at the sides 

 and having two necks ; the bodies are coarsely tuberculated and 

 the ends of the necks are set with a cycle of conical tubercles. 

 (2) Small, cylindrical, stout with two whorls, each of four thick 

 rays, on the shaft at right angles thereto ; the projecting ends of 

 the shaft with the two whorls of rays make up a ten-rayed spicule ; 

 the ends of all the rays are tubei'culated. (3) Numerous irregularly 

 formed spicules which may be compared to balls with several 

 thick rays : they seem allied to the last form, but neither axial 

 shaft nor whorls of rays can be made out. In addition to these 

 forms the polype-cells yield (4) numerous monaxile spicules about 

 one and a half times the length of the spicule (2) ; some are 

 cylindrical, others fusiform or clavate, and all are more or less tuber- 

 culated ; (5) a few cruciform spicula varied in form and usually 

 imperfect, but consisting essentially of four tapering arms at 

 right angles to each other, their bases meeting at the centre with 

 equal acute angles. (The spicula are figured on Plate YII. fig. 3.) 



This species is less robust than the other two here described, so 

 far as can be judged from the few known specimens. Three 

 examples have been obtained at Madeira at different times, but for 

 many years no others have occurred. The largest specimen was 

 presented to the British Museum, and a second, smaller, but with 

 perfect cells, was given to the Liverpool Museum. With these 

 two specimens before him, Dr. Gray (P. Z. S. 1867, p. 126) assigned 

 the latter to bis HemicoraUium johnsoni, saying it was evidently 

 the same species and showed the coral in its young state. His 

 paper is illustrated by a good woodcut (here reproduced, see p. 58), 

 which displays the entire specimen and the polype-cells. The cells 

 are unfortunately very fragile, and drop off from the dry coral at 

 the slightest touch or jar. 



The specimen in the British Museum is without its base ; it has 

 a height of 170 millim. (6^ in.) and the branches have a spread of 

 about the same. The stem below the branches has a diameter of 

 6 millim. There are four principal branches, which in their lower 

 parts vary in thickness from 4 to 7 millim. ; above, they taper 

 gradually and throw off tertiary and quaternax'y branchlets, Avhich 

 are seen to end in sharp points where stripped of the cortex. 

 Two of the branches were quite dead long before the coral came 

 from the sea, as was shown by the number of the plant-like 

 polypiaries of hydroid zoophytes attached to them. The branches 

 are often curiously perforated and tunnelled longitudinally on 

 their anterior faces, and at these places are thicker than elsewhere. 

 Boring animals appear to have attacked them, and it would seem 

 as if fresh stony matter had been secreted so as to cover over the 

 passages which are open at both ends, and the longer ones have 

 usually a series of large openings at the sides. Sometimes a 

 portion of the branch itself has been removed ; at other places the 

 stony axis does not appear to have suffered. One tunnel measured 

 35 millim. in length and had eleven openings at one side. 



