78 
TOMES : MESOZOIC CORALS OF THE COUNTY OF YORK. 
very distinct apical fossula, the well-defined cycles of septa, and 
the subcristiform superior termination of the primary septa, as 
well as the perfectly smooth sides and margin of all the septa. 
The septal fossula requires especial notice, and distinct 
definition. It is as follows : — The sef)ta forming the first cycle 
extend to the apex of the corallum and have great prominence 
outwardly as well as superiorly. Those of the second C3^cle have 
no outward prominence, being in the receding angle, but they 
also extend the whole height of the corallum. The third cycle 
consists of septa which are three-fourths the height of the 
primary ones, and the septa of the fourth cycle are a little 
shorter than those of number three. There are septa of a fifth 
cycle, which extend for a very short distance up the side of the 
corallum. 
GoNiosERis ANGULATA Duncan. 
Gonioseris angulata Dune. Supp. Brit. Fos. Cor., pt. iii., 
p. 22, pi. vii., figs. 1-5. 1872. 
After so full an account of the characteristics of the genus 
Gonioseris, as well as of the preceding species, I need only say 
of the present one that it has a much less elevated form, and 
that all its details are much less strongly made out than in 
Gonioseris Leckenhyi, more especially in the shallowness of the 
apical fossula, and in the want of prominence of 'the upper and 
inner ends of the primary septa which form it. 
Numerically it is much rarer than the preceding, one only 
having been received by the present writer to fourteen of 
Gonioseris Leckenhyi. Both species, I am informed, occur together 
in the Millepore bed of the Inferior Oolite at Claughton AVyke. 
Genus Dimorphosmilia gen. nov. 
The corallum is circular, depressed, with the upper surface 
convex, and the lower flat or concave. There is a basal wall 
and epitheca showing a central point of former attachment. The 
whole of the upper surface is calicular, and there is a central 
calice surrounded by others which are in lines in broad, open 
valleys radiating from the parent calice. The lines of calices 
