68 MADREPORARIA. 



Ill vertical sectioii tlie septa are seen to he a delicate lace-work, with perforations so large 

 and round that the skeletal matter is reduced to threads. Continuous vertical strips 

 (trabecule), however, run up in the wall and in the columella. The whole is very light and 

 porous. A tabular floor runs through the corallum, about 6-7 mm. below the surface. 



There is only one small specimen of this coral, which was the type of Mr. Quelch's genus 

 Tichopora. There is, however, no structural character which would justify its removal from 

 the genus Goniopora (see Introduction, p. 16)., 



The specimen is only 4 " 5 cm. high, and about 3 • 5 in diameter at its thickest part. 



The most striking features are : (1) the symmetry of its growth, which forms a kind of 

 transition from the hemispherical to the columnar ; (2) the regularity and symmetry of the 

 septa seen from above (see fig. 9); (3) the conspicuous interseptal loculi; (4) the large 

 reticular columella ; and (5) the inconspicuousness of the creeping edge. 



The growth-form may be due to the smallness of the object on which the colony first 

 settled (cf. the nearly similar forms assumed by some of the fossil forms (e.g. G. Sussex 1) 

 when settled on very small pebbles). Further, the calicles of these two corals are not unlike. 



For the Goniopores with large open calicles and well-developed columellar tangle, see 

 Table IV. E, p. 181. 



In fig. 9, the directives of the calicle on the left-hand lower corner run diagonally across 

 the figure from the left below, and a trough runs across the columellar tangle in the same 

 plane. The pali typically consist of two rows of three, one on each side of the directive plane. 



a. Zool. Dept. 86. 12. 9. 342. 



37. Goniopora Philippines (^4)2. (I'l. V. figs. 1 and 2.) 

 [Zamboanga, coll, H.M.S. ' Challenger ' ; British Museum.] 

 RhodaroM calicularis, Quelch {non Lamarck, see p. G4), Chall. Rep., xvi. (1886) p. 188. 



Description. — Corallum massive, rounded, slightly flattened at the top, with smooth, 

 slightly wavy surface, with hardly any trace of edges. A pellicular epitheca creeps up tlie 

 steep dying sides, and sinks deeply into the calicles. 



The calicles vary in size, mostly under 3 mm. ; deep, alveolate, polygonal or angular on the 

 top, shallow and subcircular at the sides. Walls on the top (fig. 1) thin, vertical, almost 

 membranous, fenestrated, and with denticulate edges, not thickened in the angles except where 

 young buds are forming. On the sides (fig. 2) the walls are thicker, and the tops show rows 

 of narrow septal plates. Septa everywhere obscure, hardly visible on the membranous walls 

 of the deep calicles, just visible as stria3 on the shallow lateral calicles. Deep down a few 

 thin, twisted, angular threads run out to join the columellar tangle, which, as a very irregular, 

 nearly solid tangle of coarse threads, knobs, and granules, in which a six-rayed pattern can be 

 detected, nearly closes the base of the calicle. This columella appears flat, and without pali- 

 form prominences in the deeper calicles, but in the shallower there is a somewhat symmetrical 

 ring of stout knobs rising from a nearly solid base. 



