George, James Marmion was Captain of a group designated for artillery service. His Company became an Infantry Co. in the Third Texas Infantry. The information in the files about Captain Marmion are very interesting. These are found in the Compiled muster rolls for the Third Texas. He seemed to have run afoul of some other officers and later was aboard the C.S.S. John Carr in Matagorda Bay and makes a report of the engagement of the Carr with some of the Blockading Squadron across the Matagorda Penninsula.If you are not able to get the microfilm for the Third Texas let me know and I'll see if I can get you copies.
Regards ,Charlie Peal