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180 Fossil Corals of the family Cyathophyllide. 
transverse septa and cellules, which constitute the middle of the 
corallum ; in this respect the species most Astreeoid, usually differ 
widely from true Astreas. Many of the species are simple, and 
in consequence, of their not budding, their connexion with the 
group is determined by analogies in general structure, and by 
their transitions. , 
While in a transverse section, the star of the Astreide and 
Caryophyllide characterizes a large part of the group, there are 
others closely allied, (Cystiophylla,) in which the lamella or rays, 
are barely traceable about the center of the cell, and are lost out- 
ward in a general cellular texture ; and in some of the same group, 
the rays are wholly wanting, and the texture of the corallum, in 
a transverse section, is simply porous or spumous. It is quite prob- 
able that this absence of distinct lamella, and the cellular texture 
instead, may depend, as in the Porites and Gonioporee, on the 
polyps being long exsert when expanded, only their lower por- 
tions, below the visceral cavity, secreting lime. 
In a vertical section, the transverse septa are sometimes seen to 
extend quite across the whole interior, while in other species they 
are confined to the middle portion, or become almost obsolete. 
‘They are seldom regular in their intervals, or in a simple range ; 
on the contrary there is commonly a confusion of transverse cel- 
lules through the center of the corallum. In several species, the 
septa, instead of crossing transversely, are oblique, and merely 
overlap about the medial line; while in others they extend up- 
wards very obliquely from either side, and meet more or less per- 
fectly in an axis to the corallum. Something apparently analo- 
gous to this is seen in certain Astreeas; the lamelle instead of 
- being finished out entire, have the inner edge pectinated oblique- 
ly upward, the pectinations extending toward a medial. line. 
Yet the Cyathophyllide differ essentially in having, for these ob- 
lique lines, prolongations of the intermediate dissepiments which 
unite the lamella, and not of the lamella themselves. It appears 
to be a general principle, that while these intermediate dissepi- 
ments are altogether subordinate to the lamella in the Astreide, 
in the family under consideration, they are usually stouter than 
the lamellae ; the transverse septa alluded to, result from their 
contmuation, and more or less perfect union, through the central 
"portions of the corallum, where the radiating lamelle are often 
wanting. ‘The axis, in the species with oblique ascending septa, 
