At 7:18:33 AM on Tuesday, July 6, 2010, AThompson wrote:

> Eftir þetta gengur (ganga) Vigdís inn og til erkur
> (genitive sg? of örk) þeirrar ...

> After this, Vigdís goes inside and to their large-chest
> (ark) ...

Yes, it's gen. sing.: Zoëga gives both <arkar> and <erkr>
for the gen. sing., and <erkur> is the modern spelling of
<erkr>. The gen. plur. is <arka>.

Brian