136 MADREPORARIA. 
GREAT BARRIER REEF—NO DEFINITE LOCALITY. 
All the forms which follow, except No. 37, were labelled “Great Barrier Reef,” without 
any more definite locality. Had such been given, it might in afew cases have been possible 
to assign them places near some one of the foregoing. 
No. 37 is from the “Gulf of Carpentaria—Great Barrier Reef,’ and should have been 
placed with those from the Torres Strait. I have, however, placed it near Nos. 35 and 36, 
because the growth-forms, though not exactly alike, are yet similar kinds of departures from 
the usual explanate, massive, or branching. 
For instance, the specimen registered as No. 92. 12. 1560, is so exactly like the group 
from the Torres Strait, here recorded as P. Great Barrier Reef 29, that I have not hesitated to 
place it with that group. 
125. Porites Great Barrier Reef (4932. (P. Queenslandic secunda et tricesima.) 
(Pl. XVII. fig. 8; Pl. XXI. fig. 23.) 
[Great Barrier Reef, coll. W. Saville-Kent ; British Museum. ] 
Description.—The corallum appears to creep in layers of varying thickness—1 mm. at 
the edges—irregularly over the substratum, sometimes forming hollow or solid knobs, perhaps 
in association with worm-tubes. The surface of the knobs may be smooth, or raised into 
irregular points. 
The calicles show very great variations in different parts. They are open, conspicuous, 
definitely sunk without being deep, sub-circular, or circular on smooth surfaces where the walls 
are thickened, but very angular on rougher places ; they average 1 mm. in diameter. The wall 
varies greatly in thickness. Typically, there is an elegant reticular ridge resting upon a 
more solid, sometimes strikingly flaky substructure. The variations in size and aspect of the 
calicles depends upon the development of the reticular ridge. It is sometimes a straggling 
row of narrow, elegant, spiky flakes with echinulate knobs, which may sometimes run as strie 
transversely across the wall. At others, asin Pl. XVII. fig. 8 (from specimen 8), these flakes are 
so developed as to make the calicles deep and cylindrical.* 
The septa are well developed, with a strong tendency to slant from the wall as flakes, 
sometimes very broad and rounded towards the fossa. From here they thin very rapidly, so as 
to leave wide interseptal loculi, and join a pronounced columellar tangle. All the elements 
* The appearance is as if the coral had here come against some obstruction. A proliferation 
of reticular elements is a common effect produced in growing corals when approaching too near a 
foreign body. 
