DIATOMACE^. 



115 



filled up. The waters of the Antartic Ocean are often opaque 

 and quite brown from the multiplicity of these creatures, the 



FIG. 1. DIATOMA VTJLGARIS. 



lead used on shipboard for sounding coming up from the 

 bottom covered with what appears to be mud, but which 



FIG. 2. VARIOUS DIATOMACE.S. 



on a microscopic examination proves to be nothing else than 

 the shells of these and allied species (fig. 2). Thus 



i 2 



we 



