106 REPORT—1868. 
same manner as the fish which are found in the Triassic strata and also in 
the French zone of Ammonites angulatus. Not only are these species of 
Madreporaria not rare, but they are accompanied in the Sutton stone by 
closely allied species, which of course are allied to the St.-Cassian types. 
Thecosmilia Suttonensis, Duncan, and 7. serialis, Duncan, are in structure 
and in their methods of reproduction similar to T’hecosmilia rugosa, Laube, a 
St.-Cassian species. Hlysastreea Fischeri, Laube, is accompanied by a closely 
allied species in the Glamorganshire beds ; and the genus is remarkable for its 
obyious connexion with the early secondary Astreide with more or less 
united walls. 
Rhabdophyllia is a genus closely allied to Thecosmilia, and as the forms 
included in these genera commence as simple corals, and become compound 
or serial during growth, it is obviously necessary to compare them in their 
young stage with the genus Montlivaltia. Thus MM. Milne-Edwards and 
Jules Haime say that Thecosmilice are compound Montlivaltie ; and this opinion 
is rendered important when it is remembered that some: Montlivaltiie have 
ealycinal gemmation, and thus approach the Thecosmilian type still more. 
Montlivaltia is a genus with species in the lowest coralliferous secondary 
rocks ; so that there is a fair assumption to be made that from Montlivaltia de- 
scended J'hecosmilia and Rhabdophyllia. The Thecosmilie of the Sutton stone 
are principally capitate forms; that is to say, they spring from a peduncle 
and divide suddenly (by gemmation or by fissiparity). Amongst the non- 
capitate forms is T’hecosmilia rugosa ; moreover one of the species common in 
the French zone of Ammonites angulatus is also fissiparous and non-capitate, 
viz. Michelini, Terq. et Piette. Thecosmilia Suttonensis, Duncan, has some 
resemblance to Thecosmilia rugosa, Laube, in its calice, but not in its fissi- 
parity, and it is alhied to Thecosmilia serialis, Duncan, in its short peduncle 
and capitate swelling. The origin of the corallites in 7. Suttonensis by in- 
tercalycinal gemmation is very distinctive. 
Thecosmilia serialis, Duncan, belongs to the stunted Thecosmilie so cha- 
racteristic of the Triassic and Lower Liassic coralliferous strata. It is 
readily distinguished by the number of corallites springing from the pedun- 
cle, and by its long serial calices mixed with rounded ones. 
The existence of corallites produced, in one individual, by lateral gemma- 
tion, calicinal gemmation, and fissiparity is as remarkable as is the restriction 
of other individuals of different species to one of these forms of reproduc- 
tion. 
It is necessary to bear in mind that there are these diverse methods of 
gemmation and increase in these early Thecosmilie, because the genera 
which are structurally allied, and doubtless genetically related, possess one 
or more of these methods. 
Moreover it is remarkable that the feeble true wall, the strong epithecate 
wall, the strong endotheca, the irregular septal arrangement, and the absence 
of true costee should have existed in these old secondary forms, linking them 
on to the Paleeozoic Coral-fauna in these particulars, whilst in Oolitic times 
the wall, coste, and septa became developed according to the Mesozoic type. 
The gradation of structure between the species of the genus in consecutive 
periods, however, is very palpable. 
Thecosmilia Martini and Michelini belong to the second series* ; they are 
closely allied to each other and to several British species ; they are bush- 
* The species of the 1st series are marked a in the list of the British species. 
” ” nd ” ” ” ” ” 
. 
” ” 3rd ” ” c ” ” ” 
i ell —— eee 
