Is this some kind of fungus?
 

I received a plant of Cattleya Ethel Bishop that had black markings on the leaves(first photo). They sent a replacement plant that was clean, but that soon developed the same symptoms. Can anyone explain to me what this is and what causes it?

photo 1: Attachment 73876

photo 2: Attachment 73877

The leaf on the far right in the first pic looks to me like some kind of rot or sunburn. (have you exposted this plant to strong direct sun?)
I bet it's soft and a bit wet. Cut it off and see if it occurs again.

The other black markings look like virus.
Especially the second picture, unless it was due to some mechanical damage.

Just my opinion.

I don't know that it's viral... hopefully some other members can chime in.

I'd say black rot.

Check Sue Bottom's pdf and the other litterature at STAUG

If there is any question of virus, test for it. Then you will have eliminated the biggest problem and can proceed with treatments. Were this was my plant, I would ABSOLUTELY test it! :twocents:

Cym Ladye

First pic looks like fungus. Second pic looks like insect or snail damage.