198 THE VOYAGE OF H.M.S. CHALLENGER. 
Dendrophyllia. 
Dendrophyllia cornigera, Blainville. ; 
Light and delicate specimens only were obtaimed, <A single fragmentary specimen 
was dredged together with Corallium rubrum. 
Off St Jago, Cape Verde Islands, in 100 to 220 fathoms. 
A considerable quantity was obtained at 
Station 190, in the Arafura Sea. Lat. 8° 56’ S., long. 136° 5’ E. 49 fathoms. 
Stephanophyllia, Michelin. 
Stephanophyllia complicata, Moseley (Pl. IV. fig. 12 ; Pl. XIII. figs. 3-5). 
Stephanophyllia complicata, Moseley, Proc. Roy. Soc., 1876, p. 558. 
The corallum is circular, free, and without trace of adherence; it has the form of a 
biconvex lens, the base being very slightly curved, and the upper surface greatly so. 
The under surface, or wall, is perforated by rows of oblong holes arranged in regular 
series along the interspaces between the coste. The coste are fine ridges covered with 
small swellings and granules, which radiate out with great regularity from the centre of 
the basal disk ; they commence in the centre from six very short roots of origin, which 
immediately bifurcate, thus becoming twelve. The bifurcation of each of the costal 
ridges proceeds at successive distances from the centre, until at the margin of the adult 
coral there are ninty-six costee present, sixteen in each system. The coste at the margin 
of the calicle are slightly grooved, showing a tendency to divide again. The perforations 
between the costee form about twenty-two concentrically-arranged rows. The coral is 
very convex above the septal meshwork, rising in an even curve which culminates at the 
columella. There is scarcely any central fossa. There are six systems of septa and five 
cycles. The primary septa are thin straight lamelle with untoothed margins, which 
proceed directly from the periphery to the base of the columella. At about half their 
leneth from the periphery to the centre of the calicle is a notch followed by a sudden 
rise, which forms thus a distinct palus, from the summit of which the line of the inferior 
margin of the septum slopes sharply down to the base of the columella. The secondary 
septa are also straight thin laminz ; they can be traced in the adult coral no further than 
for about one-third the distance from the periphery to the columella, since they are here 
covered by the tertiary septa, which, bending over the secondary septa at this point, 
bring together their upper margins, and, fusing with one another, form stout lamine, 
which run in a radial direction to join the columella, and are the stoutest and most con- 
spicuous septa in the coral. From their point of junction with the secondary septa, the 
tertiary septa curve outwards towards the primary septa on either side in each system ; 
and each of them being joined on its side next the primary septa by a curved quaternary 
