AUSTRALIAN GONIOPOR^. 59 



Further, an analysis of the growth of the tuft showed fairly clearly that it could be deduced 

 from a secondary proliferation of the curling-up edges of an encrusting growth. The thickness 

 of the skeletal elements at the tips of the tuft is doubtless an adaptation for strength. The 

 growth-form is figured by Mr. Saville-Kent (I.e.). 



We gather from the original description that the polyps are very extensile, and that the 

 24 tentacles are long and " awl-shaped." The oral disk is white, the column and tentacles a 

 clear liver-brown. Found at extreme low water. 



a. An encrusting form. Zool. Dept. 92. 12. 1. 167. 



b,c,d. Fragments of a tuft. „ „ 92. 12. 1. 214. 



27. Goniopora North-West Australia (6)1. (PI. III. fig. 9.) 

 [Broughton Island Eeef, 13° 44' S., 126° 11' E.. coll. Bassett-Smith ; British Museum.] 



Descriptiun. — CoraUum nearly globular, descending edges may, however, hang free, each 

 with a well-developed epitheca. 



Calicles small, 2 • 5 mm., about 2 mm. deep, subcircular and polygonal. The walls in the 

 uppermost calicles thin, sometimes membranous, and seen from above as a single stout thread. 

 Seen from the side they appear as if built up of stout, closely packed trabeculse, with a few oval 

 perforations. Elsewhere their upper edges are made ragged by the tops of the septa running 

 across them irregularly and at all angles, the radial symmetry being obscured (fig. 9). The 

 walls of the lateral calicles are thicker, owing to the greater exsertness of the septa, which, 

 however, seldom form a double row. The septa appear in three cycles round the margin as 

 uniformly but feebly developed points. Below the surface the primaries soon become con- 

 spicuous, and project inwards to form the columellar tangle. The secondaries appear to reach 

 the columella at a deeper level. The tertiaries persist as rows of minute points which, how- 

 ever, bend round here and there towards the secondaries to form the typical formula. The 

 interseptal loculi are large and open, and the skeleton is consequently not very compact ; the 

 upper edges of the primaries form a somewliat conspicuous star of rather inconspicuous 

 paliform plates or spikes, rising but slightly round the columella, which is large but 

 loosely composed of broad twisted flakes. In the lateral calicles the columella is a solid mass 

 nearly filling the shallow fossa. The primaries radiate as rows of minute points over its 

 surface. The whole of the skeleton — walls and septa — is very thin and deUcate. In section 

 the reticulum is close and solid. Tabulaj very delicate. 



This coral is quite distinct from all the others represented in the collection. It is small, 

 being about 4 cm. high, and the same in transverse diameter. There appear to be only two 

 edges, indicating one previous growth. The colony, when the first was formed, was 2-5 cm. 

 transverse diameter, and tids seems to be but loosely covered by the more recent edge. 



In the slight development of the pali in the deeper calicles, this coral stands midway 

 between those with deep calicles and conspicuous but not pali-forming primaries and those in 



I 2 



