38 MADREPORARIA. 



3. Goniopora New Ireland d)l. 

 [Holzhafen, opp. Sandwich Island, coll. German Corvette ' Gazelle ' ; Berlin Museum.] 

 "Goniopora eolumna Dana," Studer, MB. Akad. Berlin (1878) p. 524. 



Description. — Corallum columnar, 25-30 cm. high, " upper part " alone living. 



Calicles not over 3 mm. 



Polyps pale violet, very extensible, and unable to retract fully into the calicles. 



Said to be beautiful corals growing abundantly in shallow water on dead Astraeids. 

 Professor Studer compared them with Ehrenberg's " Astrcea (= Goniopora) planulata" from 

 the Bed Sea (see p. 100), but the calicles of this latter coral were 4 mm. across. 



4. Goniopora Solomon Islands ( 4)1. (PI. I. fig. 1 ; PI. XI. fig. 1.) 

 [Balalai Island, Shortland Island, Solomon Islands, coll. Dr. Guppy ; British Museum.] 



Description. — Corallum forms tall slender clusters of branches running straight up side by 

 side, 30 cm. high. The stem is at first thin, nearly round, 2 cm. diameter, very gradually 

 thickens to 3 cm. ; when about 15 cm. high, the top divides into 2 or 3 stems, which however 

 do not diverge ; some of them die down after growing 1-2 cm. The dividing tips are blunt 

 and rounded. The living layer is about 4 cm. deep, and the dead part is covered by a thin 

 pellicular epitheca which is either not continuous or else easily dissolved off. A cluster 30 cm. 

 high may consist of only three principal prongs, the rest having died down when quite short. 



The calicles at the growing tips of the branches where the texture is loose and reticular 

 differ greatly from those at the sides. The largest are 3 mm. across, angular, opening in a 

 light friable reticulum which would be purely lamellate, but for the fact that the lamellae are 

 so perforated as to make the immediate surface nearly filamentous ; they are usually shallow. 

 The walls are very irregular and fenestrated, and consist either of a single ring of trabecular 

 irregularly joined together, i. e. not continuously or regularly zigzag, or else of a jagged reti- 

 culum. The septa are represented by short points, until about 1 mm. below the surface when 

 they run out as perforate, irregularly curved plates to join a large open reticular columella. 

 In the larger calicles, traces of the typical formula can be found ; but, as a rule, they are all 

 too irregular. A group of pali with jagged or frosted points rises conspicuously almost to the 

 height of the wall. They are quite irregular in number and order. The interseptal loculi are 

 irregular. 



About 1 • 5 cm. below the growing tips, the surface texture rapidly changes from a thin 

 friable and open reticulum into a solid skeleton, built up apparently of smooth, round, closely 

 packed granules fused together (see PI. I. fig. 1). The columella gradually solidifies ; in doing 

 so it passes through a star-shaped phase in which the radial symmetry of the calicle is best 

 seen. In some the centre remains open, in others it closes ; it eventually becomes a smooth 



