446 R. F. Tomes — Inferior Oolite Madreporaria. 



from the parent calice." This is precisely what takes place in the 

 vai'ious speices of Chorisastrcea, and had those celebrated palaeon- 

 tologists seen and examined young examples at various ages, I do not 

 for a moment believe that they would have placed C. gregaria in the 

 genus Thecosmilia. 



Chorisastrcea obtusa from the Great Oolite differs chiefly from 

 the preceding in being smaller. But some of the dwarfed examples 

 of C. gregaria very closely resemble it. However, C. gregaria may 

 at all ages be known by the greater thickness of its septa outwardly, 

 that is, near the mural region. This peculiarity is observable in 

 individuals, the corallum of which is so young that it has only the 

 thickness and size of a small coin. The specimen of C. obtusa figured 

 by Prof. Duncan is not very characteristic, one of that height would 

 commonly have four or five calices, or even more. 1 Such examples 

 as the one figured are however common in the Fairford Coral-bed. 



In support of Chorisastrcea as a genus I may only remark that 

 if not Thecosmilian, the species I have here mentioned must be placed 

 either in Chorisastrcea or Latimceandra, and it can hardly be said that 

 they fall properly into the latter. 



Chorisastr-sia, sp. 

 Peduncular portions of a species of coral referable to this genus 

 have been obtained from the beds under the Pisolite at Crickley Hill, 

 and from a sandy bed overlying the Upper Lias sands at Dover's 

 Hill near Chipping Campden. All the specimens examined have 

 very numerous, thin, and uniform septa, and they are probably 

 attributable to some undescribed species. 



Genus Phyllogyra, Tomes, Q. J. Geol. Soc. vol. xxxviii. p. 430. 



Since the definition of this genus appeared, I have examined some 

 young examples of Phyllogyra Etheridgei from the Trigonia Grit of 

 Leckhampton Hill, which enable me to confirm the characters I have 

 before assigned to the genus. The smallest of these is not more than 

 an inch in diameter. It has a flattened lenticular form, with a central 

 large calice and a thin lobular outer margin, in the lobes of which 

 gemmation is actively taking place, precisely as it does in the margins 

 of small examples of Chorisastrcea gregaria. Between the marginal 

 lobes are subcristiform ridges, just as in that species, and such as I 

 have figured in plate xviii. illustrating the paper above quoted. It 

 is obviously by gemmation, and not by fissiparity, that increase in 

 this genus takes place, as the central calice is not in any way 

 interfered with by the simultaneous growth of a circle of new calices 

 in the distal ends of the surrounding septal costas. Gemmation as 

 it takes place in Phyllogyra is precisely as in Latimceandra, and as it 

 has been figured by Prof. Duncan himself in his Supplement to the 

 British Fossil Corals, plate v. fig. 7 of part ii. 



It is by no means improbable that Phyllogijra Etheridgei and 

 Chorisastrcea gregaria may prove to be forms which differ only from 

 each other ; the one by having a depressed and expanded growth, 



1 Since writing the above the specimen figured by Prof. Duncan as Thecosmilia 

 obtusa has come into my hands. Of it I shall have more to say on a future occasion. 



