Sorry for the confusion. You might want to check out a few Civil War bullet websites to view examples of these particular bullets. I'm sure the site for "Trans-Mississippi Relics" has some photos of these bullets. The "Marshall Texas" pattern is an Enfield pattern bullet (no rings) that has a distinct profile, and is only found in Confederate Trans-Mississippi sites. It is called a "Marshall Texas" pattern because a large number of them were found at the Confederate Arsenal site at Marshall, Texas many years ago.
The moniker "2-ring Mississippi" may or may not mean that it was actually used in a Mississippi rifle. This named was given to the bullet over 25 years ago and it has stuck. This bullet is also found only on Confederate sites in the TMD. In fact there are quite a few bullets found in the TMD that are not found east of the Mississippi River.
I may be able to take some photos of the bullets in my collection to give you an idea of what I am talking about. Regardless, only .577, .54, and .50 cal ammunition has been found in the sites of the 9th Battn MO SS.