ON THE BRITISH FOSSIL CORALS. 99 
The septa frequently unite by their axial ends to each other, the short to the 
long. ‘There appear to be five cycles of septa. The base of the corallum has 
a cellular tissue, probably from the fossilization of some body to which it was 
adherent. 
Height 2 inch. Breadth of base Linch. Breadth of calice } inch. 
The shape of this species is most unusual. 
These corals are all in the collection of the Rey. T. Wiltshire, F.G.S. 
It is evident that the coral evidence places the Red rock in the Upper- 
Greensand horizon. 
Corals from the Lias. 
When MM. Milne-Edwards and Jules Haime wrote their ‘ Monograph of 
the British Fossil Corals’ (Pal. Soc.),only onegood species was known as Liassic., 
There was a great paleontological break between the coral-faune of the In- 
ferior Oolite and of the Mountain-limestone. The distinction between the 
Paleozoic and Jurassic coral-faunz was so great that any student of the Me- 
sozoic Zoantharia appeared to enter another Madreporarian world when the 
Carboniferous forms were presented to his notice. On leaving the study of the 
Montlivaltiv, Thecosmilic, Isastree, and other familiar Secondary genera, and 
entering upon the investigation of such genera as Cyathophyllum, Lithostro- 
tion, Lonsdalia, and Amplewus, a new classificatory philosophy had to be com- 
prehended, and it required much experience in the habit of determining 
species before the foreshadowing of the Secondary forms could be appreciated 
in the Paleozoic. The break was produced by the very uncoralliferous na- 
ture of the Permian strata, the absence of any corals from the Trias in this 
country, and the solitary species from the Lias. 
Of late years the distinction between the Paleozoic and Oolitic coral-faunze 
of continental Europe has been lessened by the careful study by Laube and 
Reuss of the Triassic coralliferous limestones, and by De Fromentel, Ferry, 
Terquem, Piette, and Stoppani of the corals of the Avicula-contorta zone, and 
of the strata sometimes called Infralias, in which Ammonites planorbis and 
A. angulatus are found. The Palsozoic genera said to be found in the Mus- 
chelkalk and in the St.-Cassian beds were proved by Laube to be Secondary, 
and the small coral-fauna of the Lias below the zone of Ammonites Bucklandi 
(bisulcatus) was determined to be decidedly Jurassic in its affinities. The 
break was thus narrowed ; but it was nevertheless very great ; for the absence 
of any satisfactory assemblage of forms in the Permian formation and in the 
Muschelkalk rendered the aspect of the Carboniferous specific group very 
foreign to the student of the lowest Mesozoic corals. 
Some recent discoveries of Permian corals in North America do not help to 
diminish this break. 
The practical geologist will readily appreciate the vast physical changes which 
intervened between the Mountain-limestone and the Avicula-contorta beds in 
this country. The depth of the Permian magnesian and sandy deposits and 
of the Bunter on the Continent and its limestone (Muschelkalk), and that of 
the Keuper and its St.-Cassian and Késsen strata, will strike all who know 
that corals are the rarest of specimens in this pile of deposits ; so that when 
the admirable condition of preservation of the Carboniferous corals and of 
those from the Lower Lias is considered, the imperfection of the record ap- 
pears to be immense. 
The earliest evidences of the existence of Secondary corals in this country are 
the casts of simple forms, probably of Montlivaltie from the Avicula-contorta 
beds, and the casts and corallites of Montlivaltie and the Thecosmilic from the 
