Here is another picture for you
I only used that one because it is very easy to see.
It does sound like mouth fungus, which will mean you will need to add antibiotics. Salt can help, but it is not enough. To help treat this, add an airstone and turn the temperature down slowly to 72-24* (no more than 2* F per day). Some good antibiotics are Maracyn (eythromyicin), Kanacy (kanamyicin), and tetracycline if you are in the US. In the UK, you are pretty much limited to the interpet no. 9, which seem to be pretty popular.
I am not the writer of this information. Columnaris (mouth rot, mouth fungus, 'flex')
Symptoms
Early signs of this disease are greyish-white marks or patches around the mouth, or on the body or fins of the fish. These may appear thread-like, particularly around the mouth, giving rise to the incorrect name of 'mouth fungus'. Fins will deteriorate and sores may appear on the body. The gills may be affected, giving rise to bacterial gill disease. It may cause 'shimmying' behaviour in fishes like livebearers.
Causes
The disease is caused by the bacteria Flavobacterium colmnare, formerly known as Flexibacter columnaris. It has been refered to as 'mouth fungus' (even though the cause is bacterial), due to the whitish strands which may appear fungus-like. These are Gram-negative, rod shaped bacteria, which move by gliding across a surface.
As with many bacterial diseases, poor water quality is a major factor in triggering the disease. Sudden changes in conditions may also trigger it, and the disease is common in newly imported fish.
Possible cures
Anti-bacterial medications should cure this disease if used promptly. At later stages, the bacteria may invade internal organs, in which case only antibiotics may be effective. Several strains exist which vary in their virulence (how 'aggressively' they cause disease).