ON THE BRITISH FOSSIL CORALS. 79 
the Crag. As a general rule, the most preseryable and commonest of the 
true corals are not found in recent seas with Bryozoa; but certain forms 
inhabiting the sea-bottom from the lowest spring-tide level to 200 or more 
fathoms are brought up by the dredge with Bryozoa. These forms are 
strongly represented in the Crag Coral-fauna. 
List of Crag Species. 
Sphenotrochus intermedius, Miimster, sp. Cryptangia Woodii, Ed. §- H. 
Flabellum Woodii, Ed. § H. Balanophyllia calyculus, Wood. 
Sphenotrochus intermedius is found in the Coralline Crag and in the Red 
Crag of England, and it has been found in the Antwerp Crag. The genus 
still exists, and is represented in the south-western and western British and 
Trish seas. 
Sphenotrochus M‘Andrewanus, Ed. & H., the Turbinolia Milletiana of 
William Thompson, from Cornwall and Arran, is closely allied to the Crag 
species ; and it is very evident, from the variability of these simple corals, that 
Sphenotrochus Milletianus (Defrance, sp.) of the Anjou and Touraine Miocene, 
Sphenotrochus intermedius, and Sphenotrochus M‘Andrewanus have descended 
from one type, and that they have been slightly modified to meet the changes 
in the external conditions in the later Tertiary and recent seas. Probably 
these Crag and recent species should be considered varieties of the Miocene 
form. My researches in the Australian Tertiary Coral-fauna have brought 
two species of Sphenotrochus to light; but they are only remotely allied to 
the British species. 
The alliance between Flabellum Woodi and F. Roissyanum of Dax and 
Malaga, and F”. cristatum of the Bolderberg, is not close ; and the affinity 
between the British Crag species and the living F. anthophyllum, Ehrenberg, 
of the Mediterranean and Spanish coast, and perhaps from our north-east 
seas, is slight. Flabellum Woodii is closely allied to F. subturbinatum, Ed. 
and H., of the Miocene of Plaisance, and 7. Gallapagense, from the Gallapagos 
Miocene. F. Woodii is found in the Coralline Crag. 
Cryptangia Woodii, Ed. & H.—This genus is extinct, and the second 
species of it is a form very like the Crag species ; it is from the Faluns, and, 
like the Crag species, is imbedded in a Cellepore. The septal arrangement of 
the species is rather abnormal, and there is an evident tendency to revert to 
some old type in which the quaternary arrangement prevailed. The genus is 
closely allied to Rhizangia and to Cylicia. The first of these is extinct, and 
flourished in the Lower Chalk of Gosau, in the Eocene, and in the Miocene ; 
and the last is recent, its species living in the South-African and Australian 
seas. 
Balanophyllia calyculus, Wood, is represented in the Southern British 
seas by B. regia, Gosse, to which it is closely allied. The Mediterranean 
species is not closely allied ; and the same may be said for the Cape-of-Good- 
Hope B. capensis, Verrill, and the Miocene B. cylindrica. The species is 
found in the Red Crag, and the specimens are usually very badly preserved 
about the calice. The genus is fully noticed in the report on the Fossil 
Corals of the Brockenhurst beds. 
It will thus appear that three out of the four genera of Crag corals are 
represented in the existing seas of our coasts by more or less closely allied 
species. One genus is extinct. 
The fine Stephanophyllia Nysti of the Black Crag of Antwerp is not found 
in the British Crags. 
