176 K. P. TOMES 0~N THE GEEAT-OOLITE MADEEPOEARIA. 



I met with a specimen as long ago as in 1859, which, though too 

 crystalline to admit of internal examination, yet has the external 

 form well preserved, and shows that it was a thick and bushy species, 

 and probably attained to a considerable size. 



Family ASTRsEID^l. 



Subfamily Etjsmilust^. 



Genus Bathyccekla, n. g. 



The corallum is composite, compact, turbinate, and attached ; and 

 the corallites are intimately united by their walls. 



There is a common investing wall, which is costulated and some- 

 times has bands of rudimentary epitheca. 



The calicular surface is superior and convex. The calices are more 

 or less pentagonal or rounded, and deep. The septa are entire, 

 thin, and project but little into the calice ; and when they meet those 

 of other calices at the top of the wall they rise, into obtuse points. 

 The primary ones meet in the bottom of the calices and form a 

 rugged columella. At the angles where two calices meet, the walls 

 are elevated into a kind of obtuse peak. The increase is by gemma- 

 tion, which takes place only at the obtuse points just mentioned. 



There is considerable resemblance between this genus and some 

 species of the genus Stylocoenia, as S. emarciata ; but it is wholly 

 unlike other representatives of the genus, such as S. monticularia. 



Bathtccenia Slatteri, n. sp. Plate VII. figs. 1, 8. 



The corallum has a depressed turbinate form, and was attached 

 by a small surface, which in some instances was slightly pedun- 

 cular. 



The common wall is thick, and has broad and slightly prominent 

 costee, with occasional and rudimentary bands of epitheca. 



The calicular surface is convex ; and the calices (fig. 8) are penta- 

 gonal or hexagonal, but are much rounded by the septa filling up the 

 corners near the top of the wall. They are as deep as wide, and have 

 rather thin and nearly vertical walls. 



The septa are smooth, and project very little from the walls of the 

 calice. At the top of the wall, where they meet the septa of con- 

 tiguous calices, they are thickened and rise into obtuse points ; and 

 this is more especially observable of those septa which meet at the 

 point of contact of three calices. All the septa of the outer calices 

 are continuous with the mural costse of the common investing wall. 

 There are six primary septa ; they are thick and prominent at their 

 outer or upper end ; but they rapidly become thin and pass down 

 the inside of the calice like a thread, and again enlarging as they 

 pass across the bottom, unite in the centre and form a distinct but 

 rugged columella. 



The septa of the second cycle also pass like threads down the 



