series is a plural in itself
but it devilishly gets treated as a singular for most of its life, like "news"
( Grrrmachine the indifference engine, Tue 26 Dec 2006, 22:46, archived)

Ah. Interesting.
Another in the big amount of stuff I've learned today.
(Whim Devoted to destroying classic poetry with txt spk, Tue 26 Dec 2006, 22:47, archived)

just like data
but "these data" just sounds wrong
( Gilgamesh gazed in wonder as Frampton came alive, Tue 26 Dec 2006, 22:48, archived)

but you do see "datum" used sometimes
unlike "medium" (when referring to just one newspaper)
( Grrrmachine the indifference engine, Tue 26 Dec 2006, 22:49, archived)