96 . P, M, DUNCAN ON THE UPPER-GREENSAND 
concrete of the age. Almost all the species were incrusting; and 
yet some specimens are bulky, and, before the subsequent silicifica- 
tion, doubtless formed considerable masses of limestone. 
A recent coral fauna possessing the genera whose morphology is 
closely allied to those of Haldon would indubitably be regarded as 
a tropical fringing-reef assemblage, requiring a mean surface tem- 
perature of at least 74° F. The condition of the comminuted shells 
and the presence of rolled pebbles amongst the supporting rock of 
the corals of Haldon testify to the energetic action of the sea 
there. Such a condition would be favourable to the growth of 
the compound and true reef-builders of the age. The fauna is a 
poor representation of that of Gosau; but the faciesis the same. Its 
alliances with distant faunas are somewhat remarkable. Astrocenia 
decaphylla is very common in all the Upper-Greensand reefs, and 
the Southern-Indian and the West-Indian deposits of that age con- 
tain it. Stelloriais also represented in the Southern-Indian * rocks 
by a closely allied species, although those of the intermediate 
deposits of Gosau are only generally allied with the Haldon form. 
The Jsastrea I described some years since from Haldon is a multi- 
septate form akin to some from Gosau and to Isasirwa expansa of 
Stoliczka from Southern India. Finally the small Thamnastree of 
the distant deposits are closely allied to those of Haldon. 
Covered eventually by the chalk, this old littoral coral tract of this 
island must have sunk beneath the waves, and then the overcreep 
of the deep-sea ooze set in. But a deep limestone was not formed, 
and probably because the rate of subsidence was greater than the 
corresponding rate of upward coral-growth. 
DESCRIPTION OF PLATE VIII. 
. Baryhelia reticulata, sp. nov., calice and ceenenchyma, magnified. 
. Haldonia Vicaryi, sp. nov., calices, magnified. 
. The same, vertical section, showing septa and pali. 
Stelloria incrustans, sp. nov., part of surface, nat. size. 
. The same, magnified. 
. Thamnastrea Ramsayt, sp. noy., showing septa and colline, calices, 
magnified. 
. Actinacis stellulata, sp. nov., calices and interspace, magnified. 
. Actinacis insignis, sp. noy., calices, magnified. 
. Oroseris haldonensis, sp. noy., part of corallum, nat. size. 
. The same, calices, magnified. 
. Trochoseris constricta, sp. noy., nat. size. 
12. The same, part of calice and septa, magnified. 
13. Trochoseris Morrisi, sp. nov., nat. size. 
14. The same, calice, magnified. 
15. The same, synapticule, magnified. 
16. Heliopora cerulea, upper surface of corallum, natural size. 
17. The same, a calice, magnified. 
18. The same, tabulz, magnified. 
= 
ag 
——d * 
— 
— 
* Ferd. Stoliczka, “Cret. Fauna of Southern India,” Pal. Indica, ser; 4, 
vol. iy. pl. viii. figs. 4 & 5. 
