942 



T. W. VAUGHAN CHEMICAL DEPOSITS OF THE SEA 



Chemical Composition of Samples from Murray Island, Australia, as calculated 

 from their organic Ingredients and as determined hij chemical Analysis 



Specimen No. 27353ft, 1,600 feet from shore 





CaCOs. 



MgCOa. 



CaSO,. 



CasP^Os. 



SiOa and 

 (Al.Fe),03. 



Calculated 



94.3 

 93.6 



4.6 



5.8 



0.2 

 Tr. 



Tr. 



.60 



Observed 



.60 









CaCO^. 



MgCOa. 



5.8 

 5.8 



CaSO,. 



Revised 



93.0 

 93.6 



0.2 



Observed 



Tr. 







Specimen No. 27337, 200 feet from shore 





CaCOs. 



MgCOs. 



CaSO^. 



CasP^Os. 



SiOs and 

 (Al,Fe)303. 



Calculated 



93.7 



93.85 



5.0 

 5.5 



0.3 

 Tr. 



Tr. 



.00 



0.63 



Observed 



.63 









CaCOs. , 



MgCOs. 



5.5 

 5.5 



CaSO^. 



Revised 



Observed 



93.15 



93.85 



0.3 

 Tr. 



The relative importance of organisms in the samples from Murray 

 Island is as follows: 1/500 feet from shore, maclreporarian corals, 41.9 

 per cent; calcareous algae, 32.6 per cent; foraminifera, 12.4 per cent; 

 mollusca, 10.2 per cent. At 200 feet from shore the order is : Calcareous 

 algae, 42.5 per cent; madreporarian corals, 34.6 per cent; mollusca, 15.2 

 per cent; foraminifera, 4.1 per cent. 



The next two tables will bring out the similarity between the material 

 from behind the reef at Murray Island and tliat from behind the reef at 

 Cocoanut Point, Andros Island, Bahamas. 



