192 R. F. TOMES ON THE GREAT-OOLITE MADREPORARIA. 



long, thin, sometimes straight, but on some parts of the corallum 

 curved or flexuous ; and they often anastomose, especially near the 

 outer margin of the corallum, over the rounded edge of which they 

 pass. The synapticulae, viewed outwardly, are cuneiform ; that is to 

 say they consist of thin horizontal perforate laminae projecting from 

 the sides of the septa. They do not spring from the same level on 

 each septum, but, meeting those from the next septum, become oblique 

 in their position across the loculus. 



Length of the corallum 1 inch 6 lines, breadth of the corallum 11 

 lines, length of the line of calices 9 lines, height of the corallum 6 

 lines. 



It might at first sight appear that this species is nothing more 

 than a half developed form, perhaps of a Microsolena ; but this is 

 rendered very improbable by the nearness of all the calices to each 

 other, and by the great length of the septal costse. Moreover the 

 young forms of the genera Thamnastrcea and Microsolena, which are 

 common and well known, in no way resemble the present coral. v 



Genus Comoseris, d'Orb. 

 Comoseris vermictjlaris, M.-Edw. and Haime, Brit. Foss. Cor. 

 p. 122, tab. xxiv. fig. 1. 



Meanclrina vermicularis, M'Coy, Ann. & Mag. Nat. Hist. ser. 2, 

 vol. ii. p. 402 (1848). 



Only one instance of the occurrence of this coral in the Great 

 Oolite has come to my knowledge. A specimen was obtained with 

 the other species mentioned in this paper at Fairford, and is in 

 Mr. Slatter's collection. It appears to be a rare species. Only 

 two examples were seen by MM. Milne-Edwards and Haime. I 

 have already made known its occurrence in the Inferior Oolite at 

 Criokley* ; and the mention of the Fairford specimen adds another 

 locality in the Great Oolite. 



Genus Oroseris, M.-Edw. and Haime. 

 Oroseris Slattert, n. sp. Tlate VII. fig. 5. 



One specimen broken in half, but otherwise well preserved, of a 

 species of Oroseris is all that represents the genus in the Fairford 

 collection. The corallum, when perfect, had a massive and some- 

 what lobed outline, with a greatly elevated helmet-shaped middle 

 part, and an undersurface which had a corresponding and deep 

 concavity. A strongly wrinkled epitheca covers the whole of the 

 undersurface, w T hich has lines and furrows concentrically arranged. 

 The furrows of the calicular surface have a somewhat radiate direc- 

 tion from the highest part downwards and outwards, sometimes 

 running into one another; but they curve as they approach the lower 

 and outer edge, where they follow somewhat the line of the boundary 

 of the corallum. They are deep, well defined, and are about equal 

 distances apart ; and there is no part of the corallum on which the 

 calices are scattered, as in Thamnastrcea. 



* Quart. Journ. Geol. Soc. vol. xxxviii. p. 448. 



