REPORT ON CORALS— DEEP-SEA MADREPORARIA. 203 



Station 192, off the Ki Islands. Lat. 5-42° S., long. 13-2° 25' E. 129 fathoms. 

 Three specimens. 



Station 209, off Zebu, Philippine Islands. Lat. 18° 10' N., long. 123° 55' E. 95 

 fathoms. Several specimens. 



Notes on the Structure of the Soft Tissues of StephanophyUia formosissima. 



When decalcified the coral yields a plump tough mass corresponding exactly in shape 

 with that of the hardened coral before the removal of the calcareous support. A con- 

 tinuous layer of soft tissue does not, as in the case of Bathyactis symmetrica, separate 

 off from the inferior surface of the coral, and hang loose unattached to the structures 

 above it. The whole is compact and elastic, and returns to its original form after com- 

 pression. It may be cut in any direction without falling to pieces. The inferior surface 

 of the decalcified mass presents a radiate structure closely corresponding in appearance to 

 that seen on the under surface of the corallum. Five ridges of soft tissue radiate out 

 from the centre, increasing in number by division, with regularity at definite distances 

 from it, and gradually becoming thicker towards the margin of the coral. These ridges 

 of tissue occupy in the recent coral the intervals between the costas, and thus correspond 

 in position with the septa. The inferior edges of the mesenteries correspond in position 

 with the costse. 



The ridges of soft tissue lying in the intercostal grooves of the corallum are connected 

 together by series of transverse trabecular prolongations of the mesoderm which, passing- 

 through the perforations in the base of the corallum lying on either side of the inferior 

 edges of the septa (PL XVI. fig. 5), join the bases of the mesenteries where these lie 

 above the costae. Thus, by means of this series of trabecule of soft tissue, the various 

 complex ramifications of the general mass are held together, and hence the compactness 

 and elasticity of the whole decalcified coral, as opposed to the loose and disconnected 

 condition of that of such a form as Bathyactis symmetrica. Masses of contorted 

 trabecular mesoderm are developed throughout the coral corresponding in position with 

 the ramifications of the porous corallum, and a large spongy mass of this nature remains 

 behind after decalcification in the place of the columella. 



The appearance presented by the decalcified coral, when laid open by a vertical 

 incision, is shown in figure 9, Plate XVI. A short simple alimentary tube leads to a 

 wider cavity bounded by the free borders of the mesenteries with their attached 

 filaments. The mesenteries of the most inferior order spring from the upper body -wall of 

 the coral (corresponding, with the membrane forming the disc in Fldbellum) near its 

 margin, and thence are stretched to join the basal soft structures and columella. These 

 mesenteries are very narrow, and their free border is only very slightly curved. The 

 mesenteries of successively higher orders are broader and broader, have a longer stretch 



