ANALYSIS AND DISTRIBUTION OF TYPES OF CALICLE. 179 



G. Great Barrier Beef 2. 



G. Great Barrier Beef 9. Placed also in A (c). 



G. North- West Anstralia 5. 



G. North- West Australia 6. In parts (see PI. IV. figs. 4 and 5), also ^ 



in parts (PI. IV. fig. 6).* 

 G. Bhilippincs i. On the thinner parts of stock, see also under /3.* 



Doubtful :— 



G. Ne%o Guinea 1. 



G. Great Barrier Beef 3. Tending towards D. 



^. "Walls reduced to a reticulum. 

 G. Great Barrier Beef 0. 

 G. Great Barrier Beef 7, specimens a and c. 

 G. North- West Australia 6. In parts, see also under a* 

 G. PMlippincs J^. On the thicker parts of the stock, see also under a.* 

 G. Singapore If,. 



(i) Walls thin. 



a Composed of single rows of stout fused trabeculte, the tips of which cause 

 the maroins to be denticulate ; from below the edges the septa slope very 

 gradually into the depths of the calicle, so that both the paU and the 

 columellar tangle, which in the primitive shallow calicle formed a flat floor, 

 are obscured. 



G. Loyalty Islands 1. 

 G. Great Barrier Beef 7, specimen I. 

 G. Great Barrier Beef 11. Perhaps also to A (e). 

 Goniopora xd. 

 /3 The trabecule not conspicuous as such, and tending with the wall synapti- 

 culffi to form smooth lattice-works. The columeUar tangle is conspicuous. 

 G. Java Sea 1. 

 Goniopora .v a. 



G. Maldives 4.. Walls almost membranous. 

 G. Singapore 6. 

 Doubtful :— 

 G. Egypt 2. 

 . y. WaUs smooth, like membrane, and perforated with oval pores, closely 

 resembling the walls of Alveopof)-a..\ 



G. New Guinea 3 1 g^^^^^ ^g gpi^gg^ ^Iso like those of Alveopora. 



G. Great Barrier Beef 10 ) 



G. Moluceas 1. Septa as fine points. 



* These cases show how easily the radial and concentric symmetry of the wall-elements may 



break down. ... .^, ,, . , „ . 



t At the sides of all these colonies the calicles revert to the primitive type vnth thicker ^^a\\. , 

 but for this they would be indistinguishable from true Alveopom. Other forms vnth spinous septa, 

 like those of Almopm-a, are G. Red Sea 2 and Goniop,yra xc. The septa of G. Bed Sea J, are filamen- 

 tous, but hardly like those of Alvcopura. 



2 A 2 



