Brett-
The Marlin 1894 was designed to feed short cartridges like the .44-40 and .32-20 originally, and was first manufactured in 1894. The receiver is about 3/4 the size of your 1895, and the bolt is square in cross section. When the bolt is closed, it is flush with the outside of the receiver so that no ejection port shows.
Marlin made a model 1895 (starting in 1895) that was chambered for long cartridges including the .45-70. When smokeless high velocity ammo dominated the market, the 1895 was dropped. By the 1960s Marlin had one lever action left in production, the Model 336. It was chambered for longer cartridges like the .30-30 and .35 Remington. It has a round profile bolt, longer action and visible ejection port. With the introduction of the .44 Remington Magnum, and revolvers chambered for it by Ruger and Smith and Wesson in the early '60s, Marlin (and Remington IIRC) decided to develop a high-power rifle cartridge around the .44 mag's 240 grain Jacketed Soft Point. They chambered the 336 for the new cartridge and called it the model 444. In the '70's & 80's there was renewed interest in the .45-70 thanks to the Ruger Model 1 & Model 3. Marlin then took the 336, chambered it for .45-70, and named it for their earlier .45-70 rifle, the 1895.