REPORT ON CORALS—DEEP-SEA MADREPORARIA. aley 
such closely similar forms, and actually place them in separate Orders with all the 
Oculinide, Astreeidee, and Eupsammide between them. I have no doubt that the soft 
structures in the two genera will, when examined, be found to be closely similar. If the 
Rugosa are to be maintained as a separate Order, it must be retained to include only 
Paleozoic forms, which differ in more important particulars. It may be that recent 
forms, such as Duncania, form a stepping-stone to the Rugose corals generally ; of their 
close affinity with some of them there can be no doubt, when such eminent authorities as 
Duncan and Pourtalés agree upon the matter; but either those corals at present placed 
amongst the Rugosa with which they are allied must be separated from the old Order, 
or the Order itself must be given up as such. There can be little doubt that a system 
of classification which places a separation of ordinal importance between the genera 
Thecocyathus and Duncania must be in the highest degree unnatural. I have had no 
opportunity as yet of studying the structure of Paleeozoic corals myself, and therefore 
wish to write with all due deference on the matter. Professor Martin Duncan, has 
expressed somewhat similar views to me on the question. 
In examining specimens of Fhizotrochus typus in the British Museum, I was struck 
by the close similarity in structure displayed by its exothecal roots to those of Duncania. 
They are of the same texture on the surface, and are striated in a similar manner. Inside 
the calicle several thin narrow plates of hard tissue are developed running all round the 
cealicle just within its mouth, and parallel to its wall. These seem to represent the 
stereoplasma. Moreover, the septa are extremely irregular, and in neither young nor 
older specimens is an arrangement of the septa in sixes well marked. In the oldest and 
largest specimen sixteen septa are thicker than the rest, and are prominent near the 
centre of the calicle and, so to speak, “ primary.” The frequent arrangement of the septa 
in sixteens in Caryophyllia communis will be found noted under the description of that 
species. The genus Neohelia described in the sequel is remarkable for having its septa 
arranged with perfect regularity in fives, a condition which occurs also in some forms of 
Madracis. 
With regard to the distribution of the deep-sea Madreporaria, it appears that, as 
in the case of other deep-sea animals, they are mostly very widely distributed, indeed 
some, as for example Bathyactis symmetrica, have a world-wide range. Examples 
of the genus Flabellum appear to be rather scarce off the north-east American coast and 
the West Indies, and no Flabellum was described in Pourtalés’ first list of deep-sea corals 
from those localities; but Flabellum angulare was dredged by the ‘Blake,’ and a new 
species of Flabellum was obtained by Mr A. Agassiz on his late expedition. Moreover, 
Mr Verrill has described another species Flabellum goodiz, as dredged in 220 fathoms on 
the eastern slope of Georges Bank. At present the only genera which seem to be 
restricted in range are Stephanophyllia and Sphenotrochus, which have as yet been 
obtained only from the seas of the Malay Archipelago in comparatively shallow water, 
