44 MADREPORARIA. 



small size, and irregular angular outline of the calicles ; and most important of all the 

 obscuration of the septa. 



These points should lead to its re-discovery. See the table referred to for other known 

 cylindrical Goniopores, one of which (see G. New Ireland 1) Professor Studer * proposed to 

 identify with Dana's coral. 



The only columnar Goniopore with obscured radial symmetry in the National Collection is 

 G. Singajjore £?, but in this coral the lateral calicles gradually recover the typical symmetry. 

 Cf. PI. VI. flgs. 1 and 2. 



'O" 



11. Goniopora Tonga Islands (3)1. (PI. I. fig. 5; PI. XI. fig. 5.) 

 [Tongatabu, coll. J. J. Lister ; British Mu.seum.] 



Description. — Corallum forms thick cushion -shaped masses with bulging sides, which 

 develop as excrescences one upon the other, the basal being the smallest. A sharp, often free 

 edge, supported by epitheca, is traceable round each fresh growth. 



The calicles are very uniform in appearance, 3-4 mm., polygonal, open, 2-3 mm. deep. 

 Walls very uniform, thin, perforated and very zigzag along the edges, the narrow tops of the 

 radial septa of adjacent calicles alternating with one another. The synapticular bars appear 

 below the edges, which are thus raggedly denticulate. The 24 narrow septa descend straight 

 down the wall as regularly denticulate ridges, each ridge being further characterised by a still 

 finer denticulation (or frosting), only seen under a pocket lens. The two first cycles of septa 

 join the large coarsely reticular columella witliout becoming very prominent as septa, while 

 the tertiaries tend to bend round to fuse with the secondaries. 



The typical fusions take place and can be seen even with the naked eye, but the pali are 

 hardly traceable except as slightly larger curlings and frostings of the surface of the large 

 rather flaky columellar tangle ; they are most conspicuous in the shallower lateral calicles. 



The interseptal loculi are very irregular in size and are not conspicuous. 



There are three varieties of Goniopores from Tongatabu in the National Collection, the 

 one here described, and the two which are classed together under the next heading. They aU 

 agree in growth-form. This seems to consist of great rounded cushion-shaped excrescences, 

 starting on the tops of previous rounded masses, which may or may not Jiave rolled over. 

 In the one now described the stock shows a nearly regular succession of expanding cushions 

 (cf. the pulvinate method of growth, diagram C, fig. 2, p. 24, Introduction). 



The calicles in all these are about the same size, but there the likeness reaUy ends, for 

 in this coral they are very regular, with septa not conspicuously laminate (see PI. I. fig. 5), 

 with no signs of rapid growth, and with a columellar tangle which in the lateral calicles 

 becomes large, conspicuous, and almost convex. Still it is possible that very rapid growth 

 might transform it into the next type. 



a. (With a young colony attached). Zool. Dept. 1902. 9. 9. 1. 



On the original label is a note, " Polyps much extended ( • 75 inch), brown madder-colour." 



* MB. Akad. Beriin, 1878, p. 537. 



