E. E. TOMES 0]ST THE GREAT-OOLITE HADKErOEAEIA. 177 



inside of the calice, but are lost halfway down. Those of the third 

 and only remaining cycle extend but a very little way down, and 

 then thin off to nothing ; but they, as well as all those of the other 

 cycles, are thick at their upper and outer ends. 



Gemmation takes place in the angles where the calices meet ; and 

 the young calices have thick subcristiform septa (fig. 8). 



In some examples the common wall is horizontal ; and then this 

 coral bears considerable general resemblance to Isastrcea moneta 

 from the Cornbrash of Wast near Boulogne. 



The height of the corallum is from nine to twelve lines, and the 

 diameter from twelve to eighteen lines. The diameter of the calices 

 is from two to two and a half lines. 



At present it has been met with only in the Eairford coral-bed, 

 and is by no means common there. 



Bathyco^ia solida, n. sp. Plate VII. figs. 9, 10. 



The specimen consists of a portion only of a corallum, which, 

 when complete, had a diameter of several inches, and appears to have 

 been somewhat globular. 



The calices are evenly scattered over the upper and convex sur- 

 face ; they are small, and nearly circular, but with a tendency to a 

 hexagonal form, are rather deep, and regularly cup-shaped inside. 



The septa are thick and subcristiform where they meet with 

 those of other calices at the top of the wall; but they speedily 

 become thin, thread-like, and straight, and have very little projec- 

 tion into the calice. 



There are three cycles : and the septa forming the first, which are 

 six in number, pass over the bottom of the calice and, joining in the 

 centre, form a small but very irregular and spurious columella. Some 

 few septa of the second cycle do the same ; but others graduate away 

 and are lost before reaching the columella. 



The septa of the third cycle are very short, and appear as little 

 more than short cristiform ridges across the top of the wall. 



The calices have a diameter of one line to one line and a half. 



I know of only one occurrence of this species. It was found by 

 Mr. J. Windowes, of Chipping Norton, in the railway-cutting near 

 Rollright, Oxfordshire, and very obligingly given by him to me. 



Genus Convexastr^ea, d'Orb. 



The existence of this genus in England was for a long time to me 

 a matter of some doubt, no satisfactory confirmation of its occurrence 

 (as stated by MM. Milne-Edwards and Haime) having appeared. 

 The doubt was due entirely to the particular condition or state of pre- 

 servation of the specimen from which the magnified representation 

 was taken*. A comparison of that figure with the figures of 

 Conveccastrcea seocradiata given by Goldfuss f , or of C. regularis of 



* Brit. Foss. Cor. p. 209, tab. xxiii. figs. 5, 6 (1881). 

 t Petrefact. Germ. vol. i. p. 71, pi. xxiv. 



