CORALS FROM THE CORAL RAG. 93 



The branches are situated at a small distance apart, and very often they are arranged two 

 by two opposite each other ; they separate from the parent stem at an angle of about 50°, 

 and grow to some distance in a straight direction before they begin to become erect. All 

 are quite cylindrical, and the young ones are almost as thick as those of a superior order. 

 The toalls appear to be completely naked, and present closely set costce, which are narrow, 

 delicately granulated, alternately small, or larger and more prominent, quite straight, and 

 uninterrupted from the basis to the extremity of each branch, but becoming more developed 

 near their upper end. The calices are perfectly circular, and contain no columella ; the 

 principal septa meet in the centre of the visceral chamber, and become united together all 

 along their inner edge, or by means of a few thick trabiculse. There is no appearance of any 

 pali. The sej^ta are twenty-four in number, and therefore belong to three complete cycla ; 

 but there are twice that number of costge ; the fourth cyclum of costse not having any 

 corresponding septa on the inside of the wall. The septa are well developed, straight, and 

 closely set. Those of the first cyclum are thick, especially near the wall ; the secondary 

 ones are almost as strong, but those of the third cyclum are thin ; they are all but slightly 

 granulose, and constitute almost perfect laminae ; there appears to be but very few dissepi- 

 ments, and the walls are thick. The diameter of the branches varies between half a line 

 and two lines and a half. 



This fossil is found at Steeple Ashton, and is in the collections of the Museum of 

 Practical Geology, the Geological Society, the Cambridge Museum, Mr. Stokes, Mr. Pratt, 

 and M. D'Archiac. M. Roemer mentions it as being met with also in the Coral Rag, at 

 Speckenbrhike and Knebel, in Germany. 



The genus Goniocora, which we have established since the publication of the first part 

 of this Monograph, is closely allied to Cladocora and Pleurocora (p. xxxviii), by its mode 

 of generation, which always takes place by means of lateral gemmation, and not by fissi- 

 parity, as in Calamophyllia, IlhahdophyUia, and Cladophi/llia. It differs from the above- 

 mentioned dendroid Astreince by the rudimentary state of the columella and the entire 

 absence of poll. G. socialis is the only well characterised species of this new generical 

 division ; but we also refer to it a small fragment found in the trias of St. Cassian, and 

 figured by Count Munster under the name of LitJiodendron verticlllatim} This imper- 

 fectly known species differs from that here described by unequal size of the costae and the 

 verticillate arrangement of the corallites. 



1 Beitr. zur Petref., part iv, tab. xi, fig. 22. 



