11-Letter Words Matching ____O_____A

There are 30 11-letter words that match ____O_____A. 6 are common words, such as CYCLOPAEDIA and HAEMOPHILIA. A rarer one is TREPONEMATA. In this set, I is the most frequent open letter (22 words). 2 words contain a doubled letter.

Full list 30

Common words

cyclopaediahaemophiliahydrophobianecrophiliaorthodontiaphilodendraanacoluthiacycloplegiacyclothymiaenchondromahydromedusanecrophobia
cyclopaediahaemophiliahydrophobianecrophiliaorthodontiaphilodendraanacoluthiacycloplegiacyclothymiaenchondromahydromedusanecrophobianyctophobiaochlophobiaphotophobiascopophiliasinfoniettaastrocytomacladophyllahydroxyurealeukoplakianegrophobiaperionychiaprotonematarhizoctoniascolopendraspanokopitatibiofibulatreponematacoprophilia

About this list

Words
30 (6 common words)
Common example
cyclopaedia
Rare example
treponemata
Doubled letters
2
Ending in S
0
Most frequent letter
I (22)

Questions

How many 11-letter words matching ____o_____a are there?

30. 6 of them are common words.

What is a common example?

CYCLOPAEDIA is among the common words in this set.