192 



BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



List of corals obtained by Dr. Wood Jones in Cocos-Keeling Islands and their habitat- 



Con tinned. 



Name of species and growth-form. 



Habitat. 



Lagoon. 



Barrier pools 



and barrier 



flat. 



Exposed 

 barrier. 



Fungia fungites (Linnaeus), free disk 



scutaria Lamarck, free disk 



Herpetolitha crassa Dana, free coral 



Pavona danai (M. Edwards and Haime), strong folia. 



maldivensis ( Gardiner), msv 



varians Verrill, msv 



Psammocora liaiwiana M. Edwards and Haime, msv. 

 sp., incrust 



DendrophylUa willeyi (Gardiner), msv 



diaphana Dana, incrust, base, protuta. corallites . 



Astreopora myriophthalma (Lamarck), msv 



Montipora levis Quelch, br 



toTtuosa (Dana), frag., br 



ramosa Bernard, frag., br .- 



Sand 

 flats. 



Lagoon edge 



of barrier. 



X 



X 



cocosensis Vaughan, br 



spumosa (Lamarck), msv. 

 sp., lobate columns 



Especially 



inner margin 



Lagoon 



side. 



informis Bernard, msv., pi. on lower edges., 



foliosa ( Pallas), thin folia 



Aeropora pulchra (Brook), frag., br 



pharaonis (M. Edwards and Haime), br... 



forma arabica (M. Edwards and Haime) . 



corymbosa (Lamarck), corymbose 



Lagoon 

 side. 



spicifera (Dana), corymbose 



scherzeriana (Brueggemann), msv. base, stout br. 



ocellata (Klimzinger), msv. lob 



variabilis (Klunzinger), br 



palifera (Lamarck), strong br 



Poriies solida (ForskS,!), msv 



somaliensis Gravier, msv 



lichen Dana, incrust 



nigrescens Dana, br 



Millepora dichotoma Forskal, br 



Lagoon 

 inlet. 



platyphylla Ehrenberg, strong folia, 

 sp., incrust 



Inner margin 

 of barrier. 



Total number of species according to locality. 



20 



Of the 23 species found in the lagoon, 3 also occur on the exposed 

 barrier, and one of these is so modified to meet surf conditions that 

 ordinarily the specimens from the two locaHties would not be rec- 

 ognized as belonging to the same species. Thirteen per cent of the 

 lagoon species occur on the exposed barrier; while 18 per cent of 

 the exposed-barrier species occur in the lagoon. These are the 

 relations within perhaps half a mile. There are 20 species in the 

 barrier pools and on the barrier flat. Of these 6 occur within the 

 lagoon and 2 were obtained on the exposed barrier; or there are 

 30 per cent in common mth the lagoon and 10 per cent in common 

 with the exposed barrier. When such relations as these prevail 

 among the living corals of a small group of small islands, what are 

 the chances that we should among fossil corals get a large percentage 

 of common species ? 



The collection hsted shows that certain species do occur in aU 

 three habitats, and, by searching, spots may be foimd where the 



