500 MR. H. M. BEENAED ON 



the septa and pali. These threads kept the hyphal mass 

 attached to the rind after the skeleton was dissolved away. 

 Several different kinds of fungoid growths can be distinguished, 

 many presenting appearances so interesting that the whole will 

 be submitted to specialists in that branch of study, in the hope 

 that some new biological facts will be forthcoming. 



Further, in the clear spaces left by the decalcified skeleton, 

 are sections of an organism which is almost certainly a ciliate 

 Infusorian. These are essentially like those figured by Moore 

 of Spirostomum (Journ. Linn. Soc, Zool. xxiv. pi. 27), — an open 

 angular network with staining granules at the nodes, the cilia 

 not staining and passing out through a thin, deeply staining 

 membrane which, in sections, is broken up by the cilia into a row 

 of dots. How Infusoria live in the apparently solid coral I do 

 not know. It is, however, worth recording that one not infre- 

 quently finds the thinnest skeletal framework completely hollowed 

 out by a system of thin-walled tubes, so that it is in reality not 

 solid. I have never hitherto found any clue to this phenomenon. 

 The discovery of a large Infusorian in the spaces of a Porites- 

 section which are, in life, occupied by skeletal bars, adds another 

 to the organisms. Sponges, and Pungi, to whose agency the 

 excavations above mentioned might possibly be due. 



There seems to be great variation in the shapes of the polyps, 

 both contracted and protruded, judging from the published 

 figures. But it is very doubtful how far any value can be 

 attached to these variations. 



Nevertheless some of these differences should be noted. 

 Lesueur *, who first figured the polyps of Porites, shows three 

 difi'erent kinds in a species called by him " P. astrcBoides," pos- 

 sessing a large disc, and short round tentacles each with a distal 

 black point. Duchassaingt also figures a Pontes without name, 

 with large convex disc and short, slightly knobbed tentacles each 

 with a black distal point. This so far agrees with the above- 

 mentioned figure of Lesueur. AgassizJ, on the other hand, 

 gives five figures of polyps of "P. astrceoides^'' viz., a young 

 one, in which no tentacles are yet seen, and four adults in which 

 the arrangement of the parts are not at all clear. The ring of 

 lobes drawn round the mouth can hardly be the tentacles, while 



* Mem. Mu8. Paris, vi., 1820. 



t Ooraliaires des Antilles, Suppl. 1864, pi. viii. fig. 2. 



X Florida Eeef, 1880, pi. xyi. 



