34 EOCENE AND LOWEE OLIGOCENE CORAL FAUNAS. 



Siderastrea, Red Sea, Indian Oceau, islands oft' west coast of Africa, Caribbean 

 Sea. 



Balauopbyllia, Mediterranean Sea, English Channel {B. n-gia), St. Helena, Madeira, 

 Philippines, Fiji, Japan, Korea, Chinese seas, Australian seas, California, Carib- 

 bean Sea. 



Eupsaiuinia, Chinese seas. 



Endopachys, Australian seas (1), west coast of America (Coll. U. S. Nat. Mus.). 



Dendropbyllia, Atlantic Ocean, Cape Verde, Madeira, Mediterranean Sea, I'acittc 

 Ocean, Arafura Sea, Chinese and Australian seas. Bay of Panama, California, 

 Caribbean Sea. 



The foregoing table shows that the generic relations of our Eocene corals 

 are about equally divided between the mid-Atlantic and the C!hina- 

 riiilippine Islands regions. There is a great resemblance between the 

 species of Paracyathus, Balanophyllia, Siderastrea, etc., now found in our 

 West Indian region and the Eocene species of the same genera. 



MORPHOLOGY OF TIIK IHADREPORARIAK CORAL SKELETON^. 



The following account of the }trincipal. elements of the coral skeleton 

 is intended as explanatory of the terms used in the descriptive ^jart of 

 this paper. No new elements of structure are described herein, but the 

 material used in illustration has been drawn as largely as pos,sible from 

 hitherto unstudied genera and species, so that this \niYt of the paper would 

 increase our knowledge of some corals, while serving the purpose for whicli 

 it is especially intended. 



The two most important papers on this subject are von Koch's Das 

 Skelett der Steinkorallen, eine morphologische 8tudie,^ and Miss Maria M. 

 Ogilvie's ]\[icroscopic and Systematic Study of 3Iadreporarian Types of 

 Corals." Miss Ogilvie has also published many of her observations 

 in her monograph Die Korallen der Stramberger Schichten." Wilhelm 

 Volz has given a general account of the subject in his Die Korallen der 

 Schichten von St. Casian in Siid-Tirol.^ 



Besides these workers, many others have made I'areful observations on 

 the microscopic .structiu-e of the coral skeleton. Their works will be 

 referred to as occasion requires. One work, which initiated microscopic 



'Festschrift fiir Carl Gegenbaur, Leipzig, 1896, Verlag vou Wilheliu Eugelmanu. 

 ■Philos. Trans. Koyal Soe. London, Series 15, Vol. CLXXXVII. 

 aPala-ontograpbica, Snijplcmeut II, Sect. VII, 1897. 

 ^ Palaioutographicii, Vol. XLIV, Nns. 1 aud 2, 1896. 



