EXPLANATION OF PLATE XVII. 
Haly sites australis , Eth. fil. 
Fig. 1. Portion of a corallum, seen from above, showing the form of the 
reticulating laminae, and the normal corallites. 
2. Small portion of the same with the normal corallites and the 
interstitial tubes. Enlarged. 
,, 3. Portion of another corallum differing from that seen in fig. 1 only 
in the size of the reticulating laminae. 
,, 4. The same. Enlarged. 
„ 5. Portion of another corallum seen obliquely from the side, showing 
the lateral faces of the laminae, and outline of the normal 
corallites. 
,, 6. Horizontal section of part of a lamina, with two normal corallites 
and two interstitial tubes filled with crystalline calcite. 
Parts of the lamina w r alls are converted into chalcedony, 
particularly on the upper right hand ; two blebs are also 
visible on the opposite side. X 18 (about). 
„ 7 Vertical section showing two normal corallites with close hori- 
zontal tabulae, between them an interstitial tube with 
distant tabulae. The intertabular, or visceral cavities of 
the normal corallites are filled with crystalline calcite; the 
interstitial tube on the extreme right has been converted 
into a mass of chalcedony, the walls and tabulae of that in 
the centre are in the same condition, whilst scattered on 
the left hand are blebs of chalcedony. X 20 (about). 
,, 8, Vertical section of a normal corallite, highly altered. The 
tabulae and portions of the walls remain as sclerenchyma, 
the other parts of the latter being converted into blebs of 
chalcedony. The intertabular, or visceral spaces, are filled 
with crystalline calcite. X 20 (about). 
