112 REPORT—1868. 
corals; and it is necessary to assert this in collecting under one fossil species 
corals of very different external forms. The Wontlivaltie from the zone of 
Ammonites raricostatus are common, and their mineral condition has been 
preservative of the minutest details: even the granulations on the minute 
septal dentations are preserved. 
Dr. Wright collected and described a very remarkable series of corals from 
the Hippopodium and coral-beds of Marle Hill, Cheltenham, Honeybourne, 
and Fenny Compton, naming them Thecocyathus rugosus. The assemblage 
of forms thus named contains very varied specimens, the external shape 
especially being rarely alike in two or three instances. A careful examination 
of sections of most of the forms enabled me to place them all in the genus 
Montlivaltia. The absence of pali and the presence of short endothecal 
dissepiments proved that they could not belong to the genus Thecocyathus. 
But the general Montlivaltian characteristics have also the paleeozoic peculi- 
arities already noticed in considering the Montlivaltie of the zone of Ammo- 
nites angulatus. Montlivaltia rugosa, Wright, sp., will therefore take the 
place of Thecocyathus rugosus, Wright, MS. 
Montlivaltia mucronata, Duncan, is a polymorphic species, remarkable for 
its elegance and ornamentation; some of its specimens are amongst the most 
beautiful of the Madreporaria. The study of a large collection enabled 
me to place some very different-looking forms in the same species, the inter- 
mediate varieties having been in my possession. 
There is a decided affinity between these Montlivaltie and M. Stuchburyi, 
Ed. & H., of the Inferior Oolite. Moreover the WM. nummiformis, Duncan, 
of this zone is related, if structural affinity be of value, to MW. lens, KE. & H., 
Inf. Oolite. Monthvaltia radiata, Duncan, is a very abnormal species, and 
retains the quadrate septal arrangement, which is fully represented in many 
Liassic species, but which is so characteristic of many Paleozoic forms. It 
must be remembered that such strange structural peculiarities in later forms 
may arise from atavism. 
List of Corals from the Zones of the Lower Lias above the Zone of 
Ammonites Bucklandi. 
Montlivaltia patula, Duncan. Montlivaltia nummiformis, Duncan. 
—— rugosa, Wright, sp. radiata, Duncan. 
—— mucronata, Duncan. 
There are then twelve specics in the Lower Lias above the zone of Ammo- 
nites angulatus, five of which are above the zone of Ammonites Buckland. 
It needs no care to decide that the fauna of the zone of Ammonites angu- 
latus has little affinity with that of the other zones. 
Corals from the Middle Lias. 
1. Lepidophyllia Hebridensis, Duncan. 
2. Montlivaltia Victorie, Duncan. 
The first species is from the island of Pabba, and was collected by Dr. 
Wright; it forms a bed there, and was doubtless a rapid grower. 
The genus has already been slightly noticed ; its calicular gemmation and 
the growth of epitheca on the free wall of the corallites, where they grow 
higher than their neighbours, refer to an Elysastrean, Thecosmilian, and 
Septastreean series. 
A great number of specimens of all sizes of a very polymorphic Montlivaltia 
have been found on the surface of the fields at Chemington, near Skipton, and 
in a watercourse or ditch section of the Middle Lias close by. Ammonites 
