Meninges (Singular-Meninx) -
(i) Duramatter - Outer thick, fibrous attached to inner part of cranium i.e. Endorachis.
(ii) Arachnoid - Middle layer of meninges. Net like in appearance. Made up of squamous epitelium.
(iii) Piamatter - Inner most layer, thin, membranous, blood vessel present. Gives nourishment to brain. This layer enters into dorsal wall of brain & form choroid plexus or tella choroidea. In man choroid plexus are 5 (2 in lateral ventricle, 2 in 3rd ventricle & 1 in 4th ventricle) in rabbit choroid plexus are 2 (1 in dianchephalon & 2nd in medulla oblongeta).
Note :- Arachnoid and piamatter are collectively known as leptomeninges.