378 THE INHABITANTS OF THE SEA. 
CTA. X Vailiti 
PROTOZOA. 
The Foraminifera—The Amcebee—Their Wonderful Simplicity of Structure.—The 
Polycystina.—Marine Infusoria.—Sponges—Their Pores—Fibres and Spicula— 
The Common Sponge of Commerce. 
Tutnk not, reader, that the life of the ocean ends with the 
innumerable hosts of fishes, molluscs, crustacea, meduse, and 
polyps we have reviewed, and that the waters of the sea or the 
sands of the shore have now no further marvels for us to ad- 
mire. The naked eye indeed may have attained the limits of 
life, but the microscope will soon reveal a new and wonderful 
world of animated beings. 
Take only, for instance, while wandering on the beach, a 
handful of drift-sand, and examine it through a magnifying 
glass. You will then not seldom find, 
among the coarser grains of inorganic 
silica, a number of the most elegant 
shells ; some formed like ancient am- 
phore, others wound like the nautilus, 
but all shaped in their minuteness with 
Nummulina discoidals. 
a. Natural size. a perfection which no human artist 
b. c. he same, highly magnified. 
could hope to equal in the largest size. 
The knowledge of these charming little marine productions is 
of modern date, for they were first observed in the sand of the 
Adriatic by Beccaria in 1731, and for some time believed to 
belong exclusively to that gulf. At a later period some species 
were discovered here and there in England ard France, but 
their universality and importance in the economy of the ocean 
were first pointed out in 1825, by the distinguished French 
naturalist Alcide d’Orbigny. 
The sand of many sea-coasts is so mixed with Foraminifera, as 
they have been called from the openings with which their shells 
are pierced, that they often form no less than half its bulk. 
