GONIOPOKA. 159 



The only other Gonioporm showing such calicles without cohunellar floors even in the 

 shallower lateral calicles are given in Table IV. B {h) a, p. 179. 



In Dr. Briiggemann's MS. Catalogue this coral figures as " Goniopora savignyi Dana," of 

 the Eed Sea, an identification which is quite out of the question. A study of the table would 

 lead one rather to believe that the specimen belongs to the Australian or Polynesian groups. 



a, Zool. Dept. 1902. 9. 9. 16. 



150. Goniopora x e. (PI. VIII. fig. 7 ; PI. XIV. fig. 3.) 



Dcscriiytion. — Corallum forms an irregularly rounded, slightly flattened mass, either 

 growing on a short thin stalk or enveloping some point of the substratum. Living layer 

 extends right under to the area of attachment. 



Calicles small, under 2 mm., deep, angular and polygonal. Walls very thin, zigzag, jagged, 

 denticulate along the top and perforated with long oval pores, especially on the uppermost 

 surface of the corallum. The walls are nowhere reticular, not even in the lateral calicles. Short 

 stout septal spikes project irregularly from the edges of the wall, sometimes tending to be 

 plate-Uke and e.xsert. Parts of three cycles very irregularly developed. Some distance below 

 the edges of the waUs, the primaries, as rows of blunt rods, begin to project further into the 

 fossa, and still lower down, meet to form an open tangle often with a central passage. From 

 these septa in the lateral calicles six paliform rod-like processes rise up high in the calicles, 

 but are always a millimeter or so below the level of the walls. They often appear as simple 

 septal teeth bent upwards towards the aperture. The texture of the coral is very stoutly 

 trabecular. 



There is only one specimen of this coral in the collection, which is about 6 cm. long, 4 ' 5 

 across, and 3-5 high. It has been completely hollowed out by some organism (probably a 

 sponge), which has removed all traces of the attachment, so that the stock must have become 

 free. Instead of any attaching surface, there is a large round hole leading into the central 

 cavity. The destroying organism made one breach in the top surface, and near this it 

 has come so close to the surface that the calicles are open tubes, all the columellar tangle 

 having been removed. A fine thread, probably that of a boring sponge, can be seen on looking 

 through some of these open calicles. 



It is worth noting that the upper surface of the stock shows no sign of having been 

 corroded or even of having been worn by rolling. 



Dr. Briiggemann named this Ehodarcca gracilis, M.-E. & H., and it must be admitted 

 that in essential structure it bears some resemblance to G. Bed Sea 4, to which he gave the 

 same name. The walls are thicker, the calicles deeper and more pronounced, and the rod- 

 like septal apparatus does not rise to the level of the wall as it does in G. Bed Sea 4. On the 

 other hand, the stouter wall is quite what we see in the worn pebble (Goniopora xb) 

 described under G. Bed Sea 4. It is most probable, therefore, that this coral is from the 

 Eed Sea, the general structure agreeing -with that of the other forms recorded from that area, 

 and only from there. 



a. A small free stock hollowed out. Zool. Dept. 43. 3. 6. 110. 



