TURBINAEIyE BIFRONTALES. 73 



Calicles as in T. conspicua, with, however, a greater tendency to develop thick, ring like 

 margins, projecting somewhat above the surface, so echinulate as to appear furry. Septa (20 

 to 24) are perhaps thinner and less regular than in T. conspicua. The same variations in the 

 shape of the fossa and columella as in T. conspicua. 



The cccnenchyma shows a very pronounced ridge-and-furrow system, the ridges being 

 highly, echinulate and the furrows very deep. As in T. conspicua, this is more marked in 

 the younger specimens tliat in the older, but in all cases, it is more marked than in that 

 type. 



Tliis coral may be only a local variety of T. conspicua. In the unbleached state, it was 

 of a blue-grey colour, whereas T. conspicua is brown. The very pronounced ridge-and-furrow 

 system gives it a peculiar appearance. It changes colour according to the direction in which 

 it is looked at ; if seen direct, the dark furrows are most conspicuous, if sideways, the 

 whitish ecliinulations of the ridges are alone visible. 



There are five specimens forming a beautiful series illustrating the development of the 

 stock from the early cup form. 



a-d. Gulf of Carpentaria. Saville-Kent Coll. 



e. Great Barrier Reef. Saville-Kent Coll. 



(?)/. Great Barrier Reef. SaviUe-Kent Coll. [Register No. 92. 12. 1. 645.] 



Species 50. Turbinaria dendrophyllia. (PI. XXI. ; PI. XXXIII. fig. 4.) 



Description. — Corallum nearly even cup-shaped externally. Internally, infoldings of the 

 edge form vertical ridges which are wavy and divide up. A suture may or may not be visible 

 along the top of the ridge ; margin thick and crumpled. Stalk rather long, and graceful. 



Calicles not typically protuberant, but when projecting tend to put out adventitious buds 

 at the margin or to divide, giving rise to short projections or branches, consisting of bundles 

 of calicles. Calicles very unevenly distributed, varying also greatly in size, round-oval (ca. 

 2 mm.). Ca. 20 septa, almost reaching the half-radius circle, with a tendency at one or more 

 points round the calicle to meet, to form structures resembling the dendriform septal 

 arrangement of the genus Bendrophjllia. The septa slope to descend perpendicularly round 

 the rather deep fossa, in the bottom of which is a light inconspicuous columella which is 

 clearly seen to be a product of the septa. The interseptal loculi are irregularly petaloid, but 

 are not sharply circumscribed. 



The ccenenchyma is stony, the furrows being mostly shallow, while the ridges are broad 

 and bluntly toothed or granular along their crests, or else like scattered worm bu^ro^ving3. 



The tyi)e specimen is a rather deep cup 20 cm. in diameter and 12 high. Externally 

 the cup form is retained, i. e. it shows but very slight indications of the internal foldings. 

 The sutures along tiie tups of the ridges may even gai)e. 



There is one other specimen from the same district (Roebuck Bay, West Australia), 

 with respect to wiiich it is ditficult to decide whether the resemblances are due to si>ecific 

 identity or to local conditions. The dill'erences are very marked, but until we know more of 



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