42 
sea dredging lately carried on upon our coast and in Europe 
and the bearing of these specimens upon Geology, Zoology as 
well as other branches of science. The immense tracts covered 
by what Dr. Carpenter has characteristically termed ‘“ Globig- 
erima-mud,” on account of it teeming with Foramenifera so 
called and the connection of Prof. Huxley’s “ Coccoliths” and 
Coccospheres” with the formation of the chalk-beds of the 
Cretaceous open up to the microscopists an universe of new 
facts for investigation. Added to these Calcareous organisms 
the specimens of sea-bottom present us with siliceous forms, 
both animal and vegetable, of surprising delicacy and beauty 
of outline and structure and it was to these last named that 
my attention has been more particularly turned. 
Among such specimens of sea-bottom the soundings taken 
at different times and at various points on the coast of the 
United States by the Coast Survey have been subjects of ex- 
treme value to the scientific observer, while they have, at the 
same time, furnished many unscientific possessors of mi- 
croscopes with matter for admiration, wonderment and joy ; 
the graceful Diatomaceze, the symmetrical Radiolaria and mar- 
velous Foramenifera often present in such profusion serving to 
enable the preparer to put up slides of surpassing beauty. 
One of these soundings, for which I am indebted to the 
Smithsonian Institution, was of such a character that I was 
extremely desirous of studying as completely as possible the 
forms presented in it, belonging as they did to all of the three 
families mentioned, besides which it contained several minute 
mollusca and the remains of sponges and other organisms. It 
was, as 1s shown by the remains present of such a charac. 
ter as to consist essentially of Calcium Carbonate, commonly 
known as Carbonate of Lime, and Silicon Dioxide, (Silica) 
built up into the skeletons of dead organisms. The problem, 
then, presented to me was to prepare it in such a way, 
if possible, first, to show all of these objects at the same 
time or, second, to separate it into calcareous and _ siliceous 
specimens, and this last method I found, after trial, to be the 
best. As my mode of manipulation may hereafter be of 
