REPORT ON CORALS—DEEP-SEA MADREPORARIA. 135 
fine striz. The variety is nearly allied to var. epithecata of Duncan, buv as all five 
specimens of it obtained at one locality show similar characteristics, it is here named 
and figured. All the specimens have a slender, short pedicle of attachment, usually 
slightly curved. Two are attached to dead Gasteropodous shells. 
Station 192. Off the.Ki Islands. Lat. 5° 42’8., long. 132° 25’ E. 129 fathoms. 
Var. epithecata, Duncan. 
One dead worn specimen only may be referred to this variety. 
Station 219. Off the Admiralty Islands. Lat. 1° 50’ 8., long. 146° 42’ BE. 150 
fathoms. 
Caryophyllia communis, Moseley (PI. I. figs. 4, 4a, 5, 5a). 
Ceratocyathus communis, Seguenza. 
A series of specimens of this well-marked curved form, dredged in deep water off 
Nova Scotia and off the Azores, are absolutely identical with specimens in the British 
Museum from the Sicilian Tertiaries at Messina, obtained from Seguenza, and named by 
him. Many of the Challenger specimens which have evidently lain for a short time on 
the bottom in the dead condition show a slight browning of their surface, due probably 
to a deposit on them of peroxide of manganese. Some of the Sicilian specimens show 
an exactly similar browning, and are so closely alike to the deep-sea examples that were 
the fossil specimens mingled with the recent it would be impossible to separate the one 
set from the other, except by searching for matrix in the chambers of the fossils. 
All the specimens are curved and unattached. The curved pedicle is usually twisted 
to one side, the plane of curvature not corresponding with that of either the major or 
minor axis of the oval calicle. In all old specimens there is a tendency to the develop- 
ment of an epithecal covering around the pedicle and lower part of the wall. This 
epitheca appears to be composed of a dead and partly decomposed surface-layer of the 
corallum. In some specimens it is thick, opaque, and dull brownish-white, and covers 
the whole wall of the corallum nearly up to the margin of the calicle, beneath which it 
terminates in a sharply-defined boundary, surmounted by a zone of freshly formed semi- 
transparent coral substance. In the largest specimen obtained (Pl. I. fig. 4, 4a), the 
epitheca is extremely thick and conspicuous. 
The majority of specimens which may be regarded as adult, being of nearly uniform 
size, have the calicle divided into sixteen equal chambers by as many septa, which are 
alike in size and form, and in the extent to which they are exsert. Hach of these six- 
teen chambers is subdivided again by three septa, a median larger and pair of lateral 
smaller, into four equal smaller chambers. The sixteen larger septa would be termed 
primary and secondary, according to ordinary nomenclature, but they are precisely equal in 
development. There are sixteen well-developed pali opposite the septa of the next order, 
