362 Boyal Society: — 



phihelia, and a specimen of Caryoplujllia cylindracea (Reuss), 

 which were not attached, but which must have been fixed close 

 by to stones. 



As the date of the sinking of the cable was known, and as six 

 years had elapsed, it was possible to estimate the rapidity of the 

 growth of the coral on it, and also to come to some more or less 

 satisfactory conclusions regarding the rate of the deposition of the 

 foraminiferal ooze in that situation. Moreover a glance at the 

 numerous specimens showed that they presented variations and 

 abnormalities of structure well worthy of examination, and which 

 might relate to the inadvisability of retaining some of the specific 

 and generic determinations in the ancient and recent coral faunas. 



The height of the tallest* Desmophyllti^m taken from the top 

 of the cable, to which its base is strongly adherent, is If inch. It 

 is a fine and well-grown individual, being 1-|- inch in its calicular 

 length, and its hard part weighs -^ oz. There are no indications of 

 ooze having covered the base, and the granulation of the basal 

 surface is perfect and free from any evidence of erosion. 



The smallest specimen found on the cable has its calicular edge 

 rather on one side and oblique, and it is -j^ of an inch above the 

 attached base. It shows no trace of ooze ; the other specimens, 

 intermediate in size, usually present an excessively broad base below 

 the peduncle, and in some it extends for nearly | inch on all sides. 

 It consists of a layer of carbonate of lime, granular above and 

 attached below to the outer coating of the cable. 



Stunted bush-shaped masses of Lopliolulia adhered by broad 

 bases to the cable, and extended along it for many inches. The 

 corallites composing the masses were crowded together to the 

 height of an inch from the cable, and a few reached upwards 

 about I of an inch above the rest. Some had grown up obliquely, 

 and others had their calices turned downwards, so that their mar- 

 gins were not yL of an inch from the cable. They must have always 

 been above the ooze. 



Gemmation appears to have occurred four times in the tallest 

 corallites, commencing on the parent when it attained a certain 

 size : probably the parent growth occupied one year ; and there 

 were four consecutive yearly buddings. 



Prom these details it may be gleaned that the upward and general 

 rate of coral-growth at 550 fathoms is rapid in relation to that 

 noticed in Europe in the same family in shallower water. In height 

 the growth amounts to a minimum of 0-29 inch in the year, and in 

 mass it is very considerable. 



The amount of sedimentary deposit, consisting of the tests of 

 Foraminifera, sponge-spicules, and minute particles of siliceous 

 minerals, has been inappreciable on the cable during six years, 

 A few Foraminifera in crevices in the bases of a few specimens are 



* The Bcsmophylla and Lophohelia ai-e essentially oceanic deep-sea corals ; 

 they have none of the exotheca which distinguishes the rapidly growing littoral 

 reef-building forms. 



