90 P. M. DUNCAN ON THE UPPER-GREENSAND 
of their examination, published in the above-mentioned Monograph, 
showed that the following species were distinguishable :— 
Placosmilia cuneziformis, Kdw. § H. | Cyathophora monticularia, D’ Orb. 
Parkinsoni, dw. §& H. Fayvia minutissima, Duncan. 
magnifica, Duncan. Astrocenia decaphylla, Edw. & A, 
depressa, 1. de From. Isastraa haldonensis, Duncan. 
These eight species are from Haldon. 
The specimens from the Cambridge Greensand are :— 
Smilotrochus elongatus, Duncan. Onchotrochus Carteri, Duncan. 
angulatus, Duncan. 
And Farringdon yielded Smilotrochus Austeni, Edw. & H. 
The corals of the Cambridge and Farringdon Greensands are small, 
simple, and probably lived in a few fathoms of water, with their 
bases in sand or mud; but those of Haldon, mentioned above, tell a 
different story, the truth of which is enhanced by the later collec- 
tions of Mr. W. Vicary. Not only are the simple corals, the Pla- 
cosmilie, and Peplosmilic, for instance, large forms (and, indeed, some 
are as large as the ordinary simple tropical corals of the present 
day), but the last four in the Haldon list indicate the conditions of 
a fringing reef. The Jsastrwa and the Astrocenia were vigorous 
forms, and with the Yavia and Cyathophora were true limestone- 
builders. 
During the last few weeks Mr. W. Vicary has placed his collec- 
tion again at my service; and I find that the list of species requires 
much addition, and that some of the new forms are very remarkable. 
The following is the list of the new species from Haldon described 
in this communication :— 
Trochosmilia varians, Reuss. Oroseris haidonensis, sp. nov. 
Haldonia Vicaryi, sp. nov. Actinacis stellulata, sp. nov. 
Stelloria incrustans, sp. nov. insignis, sp. nov. 
Baryhelia reticulata, sp. nov. Trochoseris constricta, sp. nov. 
Thamnastreea belgica, Hdw. & H. Morrisi, sp. nov. 
-— Ramsayi, sp. noy. Helicpora ceerulea, Grimm. 
These twelve species, with the eight noticed already, and the first 
one described by MM. Milne-Edwards and Jules Haime, form the 
twenty-one species of the Haldon Greensand coral fauna. In order 
to comprehend the nature of this fauna it is necessary to consider 
the morphology of the species as explained in their description. 
Description of new Species of Corals from the Haldon Greensand, 
and notices of the previously described forms lately found there. 
MADREPORARIA APOROSA. 
Family ASTRAID A. 
Group TROCHOSMILIACEM. 
TRocHosMIrtTA vARIANS, Reuss, Denkschr. der Wiener Akad. der Wiss. 
t. vil. p. 88, pl. 6. figs. 7-11 (1854). 
The corallum is upright, straight, and has a large base; its height 
varies in different specimens. The costs are alternately rather 
