COELENTEEA— CORALS . 



53 ^ 



Ptychopliyllum, the disc-shaped Palaeocychts, the massive Gallery X. 

 colonies of Stromhodes. In the next compartment is Cysii- 

 phyllum, in which the lower part of the calyx is divided by 

 dissepiments into a vast number of tiny chambers or cysts. 

 In the allied Goniophyllum and Bhizophyllum the calyx 

 was closed by a movable lid. On the other side of the 

 Case is Cyathopliyllum, some specimens of which show 

 several young budding from the calyx of the parent. Last 

 is the allied colonial form Acerviolaria. 



Fig. 22. — Palaeozoic Anthozoa. a, a Eugose Zoantharian Coral, Omphyma 

 subtnrbinatum, from the Wenlock Limestone. About J natural size. 

 (From Prestwich's " Geology.") (See Table-case 7.) b, a supposed 

 Alcyonarian, Syringopora ramulosa, from the Carboniferous Limestone 

 of Yorkshire. Enlarged 3 diameters. (Table-case 5.) 



Of the Devonian corals, the Favositidae fill the rest of 

 Case 7. Here is Pleurodictyum, frequently associated with 

 a worm, as better seen in the specimens from the Eifel ; a 

 similar association is common in Heliofora. These and the 

 Devonian Zoantharia are mostly of the same genera as the 

 Silurian corals ; but they grew more luxuriantly in reefs, 

 which now form the massive limestones of Eifelian age in 

 South Devon. Here the specimens have to be studied in 

 polished sections, some of which are of great beauty ; one 

 may particularly note Pacliypora cervicornis in the black 



Table-ease 

 7. 



Wall-ease 

 5a. 



Table-ease 

 6. 

 Slab 

 between 

 Wall-eases 

 4&5. 



Table-ease 

 6. 



