566 PROF. P. MARTIN DUNCAN ON MICRABACIA CORONULA. 
must be, What are the thin light lines ending in thin septa at the 
margin and base of the coral (plate xiv. fig.8)? If they are coste, 
the probabilities are that the form is a Micrabacia. Again it is 
necessary to know whether the intercostal spaces of the figure (9), 
which are dark and black in colour, were not the positions of the 
small thin coste which bifurcated’ further out, and to inquire 
what are the spaces visible on the base of the magnified figure of 
the base (7). I do not feel disposed to remove the species yet from 
Micrabacia, but would rather suspend my decision until the type is 
’ found. In the mean time Micrabacia coronula, Goldf., sp., is a 
true member of the group Fungine of Milne-Edwards and Jules 
Haime. 
Discussion. 
The PresrpENtT inquired whether the fossil described occurred in 
the Cambridge Greensand. 
The AvrHor said that it did, but he thought it was as a derived 
fossil. 
Mr. CoampERNOWNE remarked on the well-marked chananten of the 
synapticula, and the relation of the fossil to the Fungide. 
Mr. Erarriper confirmed the statement that the structure of 
Micrabacia could not be seen in cut sections, but only by breaking 
the coral. 
The AurHor pointed out the peculiarities in the structure of the 
costze and septa, and thanked the President for the information 
regarding the discovery of the form in the Cambridge Greensand. 
