Major General Commandant In command of the Marine Corps, at Headquarters, Washington, D. C. Brigadier General A Brigade. Colonel A Regiment of Infantry or Artillery, or as Fleet Marine Officer of a Fleet. (In command of the Fleet Regiment of Marines when it is landed for service on shore). Lieutenant Colonel Second in Command of a Regiment of Infantry or Artillery, or as Fleet Marine Officer. Major A Battalion of Infantry or Artillery. Captain A Company of Infantry or a Battery of Artillery, or in command of a Marine Detachment of a First Class ship. First Lieutenant Junior Officer of a Company or Battery, or in command of a Marine Detachment of a Second Class ship. Second Lieutenant Junior Officer of a Company or Battery or of a Marine Detachment of a First Class ship. WARRANT OFFICERS Marine Gunners perform duty in the Marine Corps analogous to that performed by Gunners in the Navy. Quartermaster Clerks perform duties as assistants to the officers of the Paymaster and Quartermaster Departments of the Marine Corps corresponding to the duties of Pay Clerks in the Navy. NONCOMMISSIONED OFFICERS The noncommissioned officers of the Marine Corps perform duties ashore similar to those performed by noncommissioned officers of infantry and artillery in the Army and also perform duties aboard ship similar to those performed by certain of the petty officers of the Navy. The Marine Detachments assigned to some of the smaller ships of the Navy are commanded by First Sergeants. Gunnery Sergeants are assigned duties afloat similar to those performed by Gunner’s Mates in the Navy, while on shore their duties are normally in connection with the care and repair of the guns of the artillery, both heavy and light. In the Coast Guard in times of peace when the service is operating under the Treasury Department the duties of the various grades of officers are as follows: COMMISSIONED OFFICERS