Four half-men awkwardly holding hands inside four concentric bands.

[-JKP-]

Likely someone with greater knowledge and skills than mine will be able to tell us what exactly this diagram represents (there's an accompanying text in the MS).

I don't claim to have greater knowledge or skills, but I grabbed the chunk of text closest to the picture, expanded the abbreviations and got this:

Siderumque cursus naturitates ho?? a mores predicare conantur id est quis quali signo fuerit natus. aut quem effectum habeat vite qui nascitur. Cuius superstitionis genus. constellationes latini vocatur id et notatione syderum quomodo se habeant quisque qui nascitur. Primum autem stellarum  interpertes. magi nuncupantur sunt. Sed sicut de his legitur in evangelio. nato xpo annuntiaverur?/annuntiaverunt?. Postea hoc nomine soli mathematici cuius parus scientiam usque ad evangelium fuit concessa. ut xpo edieto nemo ex inde nativitatem alicuius. de cel o interpretaretur. Horos copi dicti quod horas nativitatis hominum speculantur. Capit. LXXXIII ...

Unfortunately, it isn't very helpful. It talks in generalities about astrology and horoscopy, with references to the birth of Christ, but there isn't anything specific to the drawing.

There might be something more relevant in one of the other short chapters but I don't have time to read Latin right now. My clients all need to spend their budgets before Dec. 31st and want everything at the last minute (plus I have to do tax documents), so it's crazy time from now until January.