The Contina I evolved from the Ikonta 35, as an export version. It found it's niche in the product line as a low end camera, with simple lenses and shutters, and except for the Contina II, no rangefinder. Some have exposure meters.
Quite often, when researching different cameras, you will find conflicting information in different reference books. The two reference book I'm using for this section, Zeiss Compendium, and McKeown's Price Guide seem to have conflicting descriptions of the different models that it's hard to know what is what. I've pieced together what appears to be right, but doesn't exactly match either of my reference books.
Contina I (522/24)
A compact 35mm folding camera, no rangefinder or meter. Contina on front of door. Novar 45/3.5 Novar in Prontor-SV or Tessar 45/2.8 in Synchro-Compur. 1952-55. $
Contina II (524/24)
Similar to Contina I, but with uncoupled rangefinder. 1952-53. $
Contina Ia (526/24)
A redesigned Contina I. No longer a folding camera, it has a very small viewfinder window centered above the lens. No meter. 1956-58 $
Contina Ic (10.0603)
The Contina Ia, with a facelift. Contina written in script on the front. Larger finder window off center from the lens. Again, no meter. 1958-60. $
Contina IIa (527/24)

Like the Contina Ia, but with the viewfinder moved off center to accomodate a selenium meter. I think that initally there was a small viewfinder window, which later in production was enlarged. 1956-58. $
Contina III (529/24)

An interesting concept. A low end 35mm viewfinder camera, with a selenium meter, fitted with a 45/2.8 Pantar lens The front element could be removed, and a 30mm wide angle or 75mm telephoto could be interchanged. The lenses are the same as for Contaflex Alpha, Beta and Prima. Also accepts Stereotar D. You can see these in the Contaflex page. 1955-58 $$
Contina Microscope camera
Based on the Contina III, camera has no lens or shutter. Shutter release allows film to be advanced. Uncommon.$$
Contina (10.0626)
The Contina line gets a reorganization, and this becomes the base model. Marked Contina on top. 45/2.8 pantar in Pronto shutter. No meter. Flash synch. List price in 1965 was $54. 1962-65 $
Contina L (10.0605)
As above, but with uncoupled meter. Marked Contina L on top. List price in 1965 was $59.95. 1964-65. $
Contina LK (10.0615)
The high end model of this reorganized line, it is a Contina L, but with the meter coupled to the shutter/aperture, with readout visable through the viewfinder. Identified on top. Price in 1965 was $76.50 1963-65. $
Continette (10.0625)
A budget model, with the Lucinar 45/2.8 in Pronto shutter. Zeiss never used this lens on any other camera. Identified on front, next to viewfinder. 1960-61. $