38 



Thomas G. Thompson and Tsaihwa J. Chow 



Table IV. — Strontium-calcium atom ratio of marine invertebrates coltectea at 



different tide levels 



Table V. — Strontium-calcium atom ratio of Echinodermata in relation to their 



habitats 



Table VI. — Strontium-calcium atom ratio in relation to the mineralogical 

 character of calcium carbonate in marine organisms 



* Does not include the aragonite Heliopora. 



t Does not include the calcite Anomiidae, Ostreidae and Pectinidae. 



t Does not include the calcite Errinopora. 



