OBSERVATIONS ON LIVING SPECIMENS. 13 



tribution to the mass of material. With it, in crevices of the dead 

 coral, was a new species of Haliphysema. 



On the eel-grass (Posidonia), which forms considerable areas in 

 shallow water inside the reef, there is an association of several 

 species. Iridia, Planorbulina, Discorbis, Orbitolites, with a peculiar 

 miliolid which spreads over the surface, form the greater number of 

 these. The mass of these must add appreciably to the amount of 

 carbonate of lime added to the bottom. The forms are rapid in 

 their growth, as the leaves of Posidonia are quickly covered in their 

 growth by Foraminifera and other incrusting animals. 



