Is there a prefix meaning "at most" or "capped at"? I'd like to describe a spherical cap (Wikipedia, Wolfram) that is at most a hemisphere. The blue solid in the diagram below shows the type of cap I'm comfortable referring to as a subhemispherical cap (a term I just made up to differentiate from the red solid, which is also a spherical cap,) however 'sub-' is strictly less than, whereas I mean to say less than or equal to. I thought of subhemispherical cap or hemisphere, which depicts nicely that a hemispherical cap is in fact a hemisphere, but it does sound somewhat cleaner to call it a subhemi- or hemispherical cap (although the oddity of calling a hemisphere a hemispherical cap makes me prefer the former.) I list hemi- second both times as it is the edge case.
Still, what I really want is to combine the two into one term, i.e. [prefix]hemispherical cap. This would avoid the awkwardness of those phrasings and would be an easily repeatable phrase in a paper.
By the way I do find unfortunate that the word cap here does not fit with the common English usage, synonymous with lid, if it did I could just call it a spherical cap.
Also this has to be easy to understand, if the prefix is too niche I can't use it (although I'd still be curious to hear it.)
EDITED: For extra clarity on what I want, what I came up with, and added an image.