AUSTRALIAN GONIOPORiE. 57 



This coral is at first sight very like the specimen called by Mr. Quelch "G. tenuidens" 

 (see G. moluceas 1). The form and general aspect agree, and the very fenestrated edges of the 

 walls, which are sufficiently remarkable, are somewhat alike. On the other hand, the 

 character of the septa and the absence of the pronounced plate-like pali in the deeper central 

 calicles in this case show that the two are not very nearly related. 



This specimen also is noteworthy because, as far as I can see, there is nothing but the 

 star-like group of pali in the shallower lateral calicles to distinguish it from an Alveopore. 

 The highly fenestrated, almost membranous walls and the filamentous septa, and the light 

 columellar tangle are in every respect similar, and it is only the appearance of the struc- 

 ture just mentioned which gives one any confidence in placing it in this genus. This 

 case of resemblance between forms belonging to such widely different genera is worth 

 recording (see Introductory Remarks, p. 2), and in this case it is of special interest, because 

 Alveopora] was for a long time placed among the Poritidfe (see further Table IV. B (&)y, p. 180). 



a. Zool. Dept. 92. 12. 1. 166. 



25. Goniopora Great Barrier Reef a2) ll. (PL HI. fig. 6 ; PI. XL fig. 14.) 

 [Torres Strait, (?) exact locality, coll. A. C. Haddon ; British Museum.] 



Description. — Corallum forms small erect hemispherical knobs, with short thick stalks, 

 the stock appearing to be formed of so many cap-like growths, one fitting into the other, 

 the edges either closely encrusting or sharp, free and pendent, with a projecting epitheca (see 

 PI. III. fig. 6) which may bend over as the edge dies. 



Calicles deep, conical, about 2 mm., open, irregularly angular or subcircular. Walls on 

 the top thin, irregularly denticulated by the tips of stout trabecula?, fenestrated, slightly zigzag ; 

 rapidly thickening at the sides of the stock where they are striated by septal plates or 

 granules which are often symmetrically arranged as two alternate systems. Young calicles 

 in the angles as shallow breaks in an irregular reticulum. Twenty-four septal ridges of blunt 

 frosted teeth, or rounded granules, appear on the inner faces of the walls at the margin, but 

 lower down only primaries and secondaries, the former, slightly more prominent, meet the 

 columellar tangle, on which, in the more lateral calicles, appear irregular coarse paliform 

 granules. The typical formula is obscured. 



This coral belongs to the group in which the calicles are deep, and without the rosette 

 formation except near the edges (see Table IV. p. 178). The six prominent primaries do not 

 send up paliform teeth or plates. 



There are three specimens, respectively about 2 cm., 3 cm., and 4 cm. in diameter ; the 

 largest (a) shows some five or six successive caps. These cap's appear to represent so many 

 repetitions of the primitive growth-form (see Introduction, p. 23), with the base concave rather 

 than flat, but this need be only an accidental variation. 



The cap formation is explained in the Introduction (p. 24). 



Specimen (a) retains traces of a rose-pink coloration (cf. G. Loyalty Island 1). 



a, b, c. Zool. Dept. 97. 3. 9. 91. 



I 



