50 Vereine und Anstalten, mit welchen Schriftentausch stattfindet. 
Halifax: Nova Scotian Institut of Science. 
Minnesota: Minneapolis Geological and Natural History Survey 
of Minnesota. 
New-Haven: American Journal of Science and Arts. 
Philadelphia: Academy of Natural Sciences. 
Rio Janeiro: Museo nacional. 
Salem: Am. Association for the Advancement of Science. 
Santiago: Deutscher wissenschaftlicher Verein. 
San Jose: National-Museum der Republik Costa Rica. 
San Fancisco :: California Academy of Natural Sciences. 
St. Louis: Academy of science. 
h Missouri Botanical garden. 
St. Paulo: Societ& geographique et geologique, (Brasilien). 
Toronto: Canadian Institute. 
Washington: Departement of Agriculture of the United States 
of N. America. 
. Smithsonian Institution. 
United States Geological Survey. 
