One might argue that it's a particular kind of partitive that I once
learned to call "genitive of the target"--or a genitive of the sphere
within which; but it's probably simpler to think of it as genitive with the
verb KATAXEW; in general verbs with prefix KATA- tend to be construed with
a genitive.
Carl W. Conrad
Department of Classics, Washington University
One Brookings Drive, St. Louis, MO, USA 63130
(314) 935-4018
cwconrad@artsci.wustl.edu OR cwc@oui.com
WWW: http://www.artsci.wustl.edu/~cwconrad/