26 



BRITISH FOSSIL CORALS 



lar and sometimes as encrusting forms. All are very irregular in their septal arrange- 

 ment, and none of them present definite and clear cyclical sequences. 



Some of the species have the coenenchyma between the calices irregularly ridged, so 

 as to present the first traces of that coeuenchymal development which characterises the 

 genus Sfi/locoenia. The columella is very distinct in all the species, and the junction of 

 the laro-est septa to it is marked in some forms by a paliform svveUing, but there are no 

 pali. In many species the smaller septa unite more or less to the larger, and in others 

 the dentate condition of the septal edge is very marked. The costae are either rudi- 

 mentary or well developed in different species; they may be straight, spined, and 

 wavy. 



The size of the corallum, its shape and its habit, with the size of the calices, and the 

 character of the costae and of the coenenchyma, appear to separate certain forms from 

 others and enable eleven new species to be classified with the Astroccenice . 



The following scheme of the structural peculiarities of the new Astrocoenice will show 

 hoAV readily their specific distinctions may be recognized : 



ASTROCCENIA. 



Corallum 



large 



(small 



gibbons and tall 



fliu aiul short . 



short, and irregular in outline 

 ' encrusting 



pedunculate, witb an epitbeca 

 dendroid 

 flat and narrow 

 globose .... 

 irregular 

 flat and semi-encrustiiiir . 



Astrocoenia gibhosa. 



— plana. 



— insignis. 



— reptans. 



— parasitica. 



— pedunculata. 



— dendroideu. 



— sicperba. 



— favoidea. 



— costata. 



— minuta. 



Corallum having the coenenchyma 



scanty 



abundant 



moderately developed 



Astroccenia favoidea. 



— minuta. 



— parasitica. 



— dendroidea. 



— super ba. 



— pedunculata. 



— insignis. 



— reptatis. 



— costata. 



— gibbosa. 



— plana. 



