CORALS AND CORALLlFOltM TYPES. 47 



Fain. 1. Cyclinicld: : — Corallum simple, disciform. 



Group A. — S/miferi: Septa represented by longitudiual rows ol' short spines. 

 Aainthocyclifs, Dyb., Sil. 



Group B. — AUernali: Septa, alternating in length, regularly arranged. 

 Palmocyclus, E. & H., Sil. 



Group C. — Sulcati: Cup with one or more septal furrows, towards which some of 

 the septa commonly incline. 



Mitroci/cltis, Meek, Dev. 

 Campo/)hi/l/iim, E. & H., Dev. 

 Bari/iihyllam, M. Ik B.., iJev. 

 Hadrophi/llnm, E. & H., Dev. 



Fam. 2. Pe/raiefe .--Corallum simple, conical, straight or curved, without columella. 



Pelraia, Munst., Sil., Dev., Carb. 

 PolyccBHn, King., Pala'ozoic. 

 Kenophyllnm, Dyb., Sil. 



Fam. 3. Cyatkaxonidic : — Corallum coniform, simple, a central columella present. 



Cyitthdxoniit, Mich., Sil., Dev., Carb. 

 Duncanel/a, Nichol., Sil. 

 Duncania, de Kon., Carb. 



