Taxonomy Help Needed

Wed Jun 19 01:19:07 EST 1996

Over the past two weeks, I have been puzzling over a strange organism which I
found in a freshwater sample.  I rpovide a description below and would greatly
appreciate any help in identifying this organism. 

Description of Unknown Entity
	In examining a sample taken from a roadside ditch which was rich in
algae, I noticed, several weeks later, an odd entity at the bottom of the
sample.  I am assuming (with little justification) that it is some sort of
alga.  The key characteristics which I have been able to discern thus far are:

1)  It is found in freshwater.
2)  It is shaped like a miniature volcano and is calcareous.
3)  The "cone" of a typical organism is about 180 microns in diameter and
	extends upwards perhaps 40-50 microns.
4)  The cone of the organism is highly birefringent and produces a striking
	Maltese cross under crossed polars.
5)  The cone dissolves immediately in 10% HCl and slowly and observably in 1%
	acetic acid.  When observing the rounded peak of the cone, there appear
	to be projections which at first glace looked like sand grains. 
	However, when treated with acid, they too dissolved.
6)  When treated with Methyl Green Acetic, the cone slowly idssolves and what
	remains is a disk-shaped layer which takes up the stain.  The organic
	disk shows very little in the way of differentiation or even much to
 	suggest cell structure.
7)  The underside of the cone is hollow.
8)  The crystals along the edge are very minute and densely packed to give an
	almost feathery appearance.
9)  A significant number ofthe specimens look like two of the cones have fused
	and that there is a line of connection between the two halves; in other
	words, it appears as though the organism is dividing.
10)  It is no uncommon to find clumps of the organisms consisting of six,
	eight, or even more joined together in irregular patterns.
11)  After dissolving the calcareous cone, I treated the remaining disk with
	Acridine Orange.  There were many very samll points of typically bright
	light green fluorescence, but no discernible larger structure nor any
	apparent patterns among the points.

I have checked a variety of references and have been unalbe to find any
references to calcareous freshwater algae, except for the mentions of lime
structures in genera such as *Chara*.  If anyone can provide any suggestions
about what this creature might be or where I might look to get further
information, I would be most grateful.


Richard L. Howey
University of Wyoming 
P. O. Box 3392
Laramie, WY   82071

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