DISTRIBUTION OF FOLLICULINA IN 1914. 



E. A. ANDREWS. 



The finding of vast hordes of the Stentor-\ike infusorian Follicu- 

 lina both in 1912 and 1913 throughout the whole extent of the 

 Severn River which is a brackish side branch of the Chesapeake 

 Bay, led to further examination in 1914 to see if this were a 

 phenomenon to be repeated annually or only a rare inroad of an 

 outside fauna into new territory. 



In I9I3 1 FolHculina'was found in inconceivable numbers living 

 upon the leaves of the fresh water plants Elodea and Potamogeton, 

 which have taken possession of definite zones of shallow brackish 

 water along some fifty and more miles of extent of the river and 

 its side creeks. It was also found on Elodea in Whitehall River, 

 just to the north of the Severn. 



In 1914 it was taken on Elodea from the head of the Magothy 

 River, August 13, and on floating Elodea in the mouth of the 

 Magothy, August 23, when it was also found living upon stunted 

 Elodea growing in the narrow inlet canal to the nearly shut off 

 side branch known as the Little Magothy. It was taken also 

 at Deep Creek, a side branch of the Magothy. 



As the Magothy opens into the Chesapeake some seven miles 

 from the Severn, the distribution of Folliculina is quite extensive. 

 Moreover, in 1880 Ryder 2 found Folliculina in great numbers 

 upon oyster shells in shallow water on the west coast of the 

 Chesapeake, and as he seems to have then been at St. Jerome, 

 St. Mary's County, which is sixty miles down the Bay from the 

 Severn, the distribution of Folliculina is known for side branches 

 of the Bay opening into it seventy miles apart, approximately. 



It is to be expected then that exceedingly large areas of the 

 side waters of the Chesapeake may be inhabited by this little- 

 known protozoan, which in the mid-summer season adds greatly 



1 See BIOL. BUI.L., XXVI., No. 4, April, 1914. 



2 Am. Nat., 14, 1880. 



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