That portion of the pia mater that covers the ependymal roof or, in the case of the lateral ventricle, medial wall of a cerebral ventricle. ... (05 Mar 2000) ... 
Type: Term Definitions: 1. that portion of the pia mater that covers the ependymal roof or, in the case of the lateral ventricle, medial wall of a cerebral ventricle. Synonyms: choroid membrane