Correct spelling for the English word "aquula" is [akwjˈʊla], [akwjˈʊla], [a_k_w_j_ˈʊ_l_a] (IPA phonetic alphabet).
The endolymph (a. interna) and perilymph (a. externa) in the membranous labyrinth.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.