Illustrations of the 12 zodiac constellations or zodiac signs can be found in (at least) three different types of treatises.
1) Astronomical;
These tend to show all constellations in three parts: North of the ecliptic, at the ecliptic, and south of the ecliptic. The second part is the set of 12 zodiac constellations. This always refers to constellations, not signs of the zodiac.
2) 'Astrological' or horoscopes;
These show emblems of the 12 zodiac signs. Often, they also show more detailed subdivisions into 36 decans, or 360 degrees.
3) Calendars or books of hours;
These also show emblems of the 12 zodiac signs, often with a parallel cycle of 12 emblems for the months, i.e. what are typical activities performed during this month.
Zodiac is therefore the more neutral term, and it does not say anything about the intention of the illustrations. Talking about constellations, or calling it a calendar makes it more specific.
The nice articles by Marco and Darren at Stephen's blog, and JKP at his own blog, tend to include illustrations both fromgroups 2 and 3 above. The well-known quote from Dr. Stolot suggests a possible connection between the Voynich MS zodiac and group 3, based on details in the drawing.
Illustrations that include indications of the stars tend to come from group 1, but I believe that they can also come from group 2. People who have looked at all these illustrations in more detail may be able to be more specific about that point.
1) Astronomical;
These tend to show all constellations in three parts: North of the ecliptic, at the ecliptic, and south of the ecliptic. The second part is the set of 12 zodiac constellations. This always refers to constellations, not signs of the zodiac.
2) 'Astrological' or horoscopes;
These show emblems of the 12 zodiac signs. Often, they also show more detailed subdivisions into 36 decans, or 360 degrees.
3) Calendars or books of hours;
These also show emblems of the 12 zodiac signs, often with a parallel cycle of 12 emblems for the months, i.e. what are typical activities performed during this month.
Zodiac is therefore the more neutral term, and it does not say anything about the intention of the illustrations. Talking about constellations, or calling it a calendar makes it more specific.
The nice articles by Marco and Darren at Stephen's blog, and JKP at his own blog, tend to include illustrations both fromgroups 2 and 3 above. The well-known quote from Dr. Stolot suggests a possible connection between the Voynich MS zodiac and group 3, based on details in the drawing.
Illustrations that include indications of the stars tend to come from group 1, but I believe that they can also come from group 2. People who have looked at all these illustrations in more detail may be able to be more specific about that point.