3S8 James on Moyiticulipora. 
mainly to deal. The class Aitthozoa has been divided into 
three great orders, namely, Zoantharia^ Rugosa^ and Alcyofi- 
arici. The Zoantharia again have been divided into three 
groups, one i^AIalacodermata) including the sea-anemones, in 
w^hich there is either no skeleton at all, or else a pseudo-skeleton 
made up of scattered spicule; a second, (^sclerobasica') in which 
the colonies are more or less branched and fleshy; and a third 
{^sclerodermata') in w^hich a true calcareous corallum is alw^ays 
developed. It is this last group of the three w^ith which we 
now have to deal, as it is only here that the forms are preserved 
in a fossil state in any numbers. 
The scelroder?)iata^ then, have been divided by the great 
authorities, Edwards and Haime into four sections, namely, 
Aporosa^ Perforata, Tabulata^ and Tubulosa. In the Apo7-osa 
are found mainly living genera. The corallum is made up of 
a great number of tubes which are divided longitudinally by 
well developed septa; while cross partitions, tabulte, are rarely 
found. Favistella is probably an example of this group. In 
the Pe7-forata the septa may be well or may be only slightly 
developed, and in some cases the tubuli are crossed by tabulte 
while in others they are open. The walls are vei'y generally per- 
forated. This group contains many fossil genera, such as Pro- 
taroea and probably the Pavositidce. The third group, the 
Tabulata^ originally formed to contain those corals in which 
septa are scarcely developed at all and tabular are well de- 
veloped, seems such a mixed collection of forms that it has 
been proposed to break it up and distribute the genera else- 
where, or else greatly restrict its limits. Of the genera form- 
erly included in it, some have been transferred to Hydrozoa 
(JMillepora for example, though this has also been placed in 
the order Alcyonaria), some have gone to Perforata (e. g-. 
Favositidce')^ while others have been transferred to the order 
Alcyonaria ( e. g. JMontiadiporidce and Helioporidie). Of 
these last two families we shall have more to say directly. Lastly 
the Tubulosa constitute a small group to which belongs Aulop- 
ora and possibly Stofnatopora. These present some affinities 
to the Polyzoa, and may have to be transferred there. These 
then are the groups of Zoantharia sclerodermata. Let us turn 
now to the second order, or 
