"(and no primer)"
Nope. They were externally primed, like the Burnsides, Gallagher, and Smith carbines of the same time frame (Civil War era). The cartridge was loaded and a percussion cap placed on a nipple to fire the round.
Cartridges and carbines like these are best termed transitional, because they fall right in between the muzzle loading caplock rifled musket and the breech loading rim and center fire weapons like the Spencer and later Winchesters.
Here's an article on the Maynard carbine (a reproduction in this case) showing both the carbine with separate priming nipple and a picture of the case and other components.