Corals dredged by H.M.S. ( Challenger' 



567 



coides, and C. nobilis have been dredged but once, two specimens of the 

 first of the three having been obtained, and only a single one of each of 

 the others. Ceratotrochus platypus was obtained off the coast of New 

 South Wales ; the other three species of Ceratotrochus in the Atlantic. 

 These Ceratotrochi appear not to occur in the Pacific, nor in the seas of 

 the East-Indian archipelago and Philippines. In the deep waters about 

 the Philippines and near the Ke Islands their place seems to be taken by 

 the Stephanophyllias and Platytrochus rubescens and Deltocyathus mag- 

 iiificiis. 



Families and Genera of Corals occurring in the Deep Sea. 

 The following is a list of the genera of corals as yet obtained from the 

 deep sea from depths of 50 fathoms and upwards, compiled from Count 

 Pourtales's and Professor Martin Duncan's works, and from the prelimi- 

 nary determinations of our own series made by myself, which will, how- 

 ever, I expect, need some modifications hereafter, but not such as very 

 materially to alter the results. 



List of Genera of Corals obtained by the U. S. Coast Survey, H.M.S. i Por- 

 cupine^ and H.M.S. ' Challenger] in depths of 50 fathoms and 

 upwards. 



Turbinolid^e. 

 Caryophyllia. S. T. 

 Coenocyathus. S. 

 Acanthocyathus. T. 

 Bathycyathus. S. 

 Stenocyathus (Pourt.). 

 Trochocyathus. S. T. 

 Thecocyathus. S. 

 Leptocyathus. 

 Paracyathus. 

 Deltocyathus. T. 

 Sphenotrochus. T. 

 Platytrochus. T. 

 Ceratotrochus. T. 

 Sabinotrochus (Duncan). 

 Desmophyllum. T. 

 Flabellum. T. 

 Rhizotrochus. 



Oculinid^e. 

 Oculina. T. 

 Cyathohelia. 

 Lophohelia. T. 

 Amphihelia. S. T. 



Stylopuoridje (Pourt.). 

 Madracis. 



ASTR/EID/E. 



Parasmilia. S. 

 Coelosmilia. S. 

 Solenosmilia (Duncan). 

 Astraeacese (genus of). 

 Cladocora. 



Stylasterid.e (Gray). 

 Stylaster. 

 Allopora. 

 Cryptohelia. 

 Distichopora. 

 Erriua. 

 Lepidopora (Pourt.). 



Eupsammid^e. 

 Balanophyllia. T. 

 Stephanopbyllia. S. T. 

 Thecopsammia (Pourt.). 

 Dendrophyllia. T. 



FuNGIDjE. 



Fungia. 

 Diaseris. 



MlLLEPORIDiE. 



Pliobothrus. 



Rugosa. 

 Haplophyllia. 

 Guynia. 



Note.— S. after the name denotes that the genus occurs in Secondary formations, 

 T. in Tertiary formations. 



