adventitia, tunic, tunica
membrane
lens capsule
theca
meninx
veil, velum
skim
diaphragm
head
lamella
film
pellicle
film, membrane, pellicle (gloss)
membrane (gloss)
diaphragm (gloss)
(hypo)
membrane, diaphragm (gloss)
(ellipsis of)
slide (gloss)