12 



THE INORGANIC CONSTITUENTS OF MARINE INVERTEBRATES. 



2. Alcyonium palmatum. Probably Mediterranean. 



3. Corallium rubrum; the precious red coral. Mediterranean. 



Analyses 2 and 3 by 0. Butschli in K. Gesell. Wiss. Gottingen Abh., No. 3, 1908. 



Older analyses of alcyonarums. 



CaCOa 



MgCO, 



"Phosphate". . 



CajPA 



Fe^Oa 



CaS04.2HjO.... 



SiO, or sand 



Hjd 



Organic matter. 

 Insoluble 



93.39 

 6.00 



.10 



Trace. 

 .30 



.05 



99.84 



100. 33 



99.32 



^ The reduced analyses, rejecting obvious impurities, are as follows: 



Reduced analyses of alcyonarians. 



That these analyses fit well into our own series is evident. 



In a worked specimen of Corallium rubrum, H. W. Nichols found 9.32 per cent of magnesium 

 carbonate, not far from Biitschli's figure. In Eunicea tourneforti and Plexaurella dichotorna, both 

 from the Bahamas, he found, respectively, 2.78 and 2.11 per cent. These percentages, how- 

 ever, are based on crude material; that is, without rejection of organic matter and water. 

 They are, therefore, unavailable for comparison with our reduced analyses. Three similar 

 analyses by G. Forchhammer '= are also recorded, of Tubipora musica, Corallium nobile (=C. 

 rubrum), and his hippuris, which gave, respectively, 3.83, 2.73, and 6.36 per cent of magnesium 

 carbonate. These data lack sufficiently expHcit details to admit of comparison with ours. 

 ^Vliy his figure for the red coral is so low is not clear. The material taken for analysis must 

 have been quite different from that used by Nichols or Butschli. A still eariier analysis of 

 red coral by Witting '^ gave 3.50 per cent of magnesium carbonate. The specimen analyzed, 

 however, contained about 12 per cent of impurities. 



If, now, we arrange the alcyonarians in the order of ascending magnesium carbonate, a 

 remarkable relation connecting composition with temperature appears. Heliopora, being 

 anomalous, is not included in the table. The three analyses by Anderson and Butschli are, 

 however, inserted. Localities and latitudes are abbreviated. The percentages of magnesium 

 carbonate are from the reduced analyses, and those of calcium phosphate are also given. 



" Forchhammer, 0., Neues Jahrb., 1852, p. 854. 



"Wittins, E.. .\nna!ea Chem. i!. Pharm., 



vol. 1, p. 119, 1S32. 



