A new Alga for me...

Now that we're in the depths of winter I have little of waterborne interest to investigate. I do have a few water containers sitting in a basement window sill that have some algae from my aquarium growing in them. This afternoon I noticed a new growth on the glass side of one bowl and managed to scrape a bit off to view under the microscope. It turned out the specimen was a radial, flattened and multicellular alga that I had never seen before. I'll try to find out what it is but until I do here are a few images I took at various magnifications. After a bit of sleuthing it looks like its a member of the genus Coleochaete , possible orbicularis.

 Here it is at 40X. It appears to have grown out from a central cell and has retained a fairly symmetrical appearance.

This image has been cropped from a 100X magnification photo. The symmetrical growth is very evident here.

Here is a final image with a magnification of 400X. A scale bar indicates the cells are from 15 to 20 microns long.

A green diatom...

We're into the depths of winter here in Manitoba and my favorite haunts are sitting under a couple of feet of ice. The mini and micro aquariums have basically died out except for the odd rotifer or ciliate. All except for one little jar, where it seems conditions are ripe for a number of diatoms. With not much else to look at I've started reading about, and focusing my photography efforts on, diatoms.

No idea what this specie or even genus is but I was struck by the fact the chlorophyll withing the frustule was green. Based on observations and my reading this is a fairly rare occurrence.
It wasn't moving so it may belong to the genera that lack raphe or it just may be dead and perhaps the green color is an artifact resulting from that.

I thought this specimen was rather neat in that the shape was so different than anything else I had seen before. It was moving so it is a member of the diatoms with at least one raphe.This is possibly an individual from Achnanthes inflata.