From the MLA Handbook for Writers of Research Papers, Seventh Edition, section 3.7.5. "Ellipsis":
For an ellipsis within a sentence, use three periods with a space before each and a space after the last ( . . . ).
As an example it shows:
Quotation Omitting a Sentence
In discussing the historical relation between politics and the press,
William L. Rivers notes:
Presidential control reached its zenith under Andrew Jackson, the
extent of whose attention to the press even before he became a
candidate is suggested by the fact that he subscribed to twenty
newspapers. . . . For a time, the United States Telegraph and the
Washington Globe were almost equally favored as party organs, and
there were fifty-seven journalists on the government payroll. (7)
So there are no
(). For my MLA papers, I have a macro for the "quotation-ellipsis":
The small space
\, takes care of some weird spacing in
\ldots, that seemed to look best to me.
\xspace makes sure it works as
bla bla \el. and as
bla \el bla., i.e. a space is added only if there's no punctuation after the macro. The
ellipsis package might be even better for this purpose, but I've never really looked into it since this solution worked for me.