UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13D

                    Under the Securities Exchange Act of 1934
                               (Amendment No. 4)*

                             Mylan Laboratories Inc.
                                (Name of Issuer)

                     Common Stock, par value $.50 per share
                         (Title of Class of Securities)

                                    628530107
                                 (CUSIP Number)

                              Keith Schaitkin, Esq.
                            Associate General Counsel
                  Icahn Associates Corp. & affiliated companies
                          767 Fifth Avenue, 47th Floor
                            New York, New York 10153
                                 (212) 702-4380

           (Name, Address and Telephone Number of Person Authorized to
                       Receive Notices and Communications)

                                November 22, 2004
             (Date of Event which Requires Filing of this Statement)

If the filing  person has  previously  filed a statement on Schedule 13G to
report the  acquisition  that is the subject of this Schedule 13D, and is filing
this schedule  because of Section  240.13d-1(e),  240.13d-1(f) or  240.13d-1(g),
check the following box / /.

NOTE:  Schedules  filed in paper format shall include a signed original and
five copies of the schedule,  including  all  exhibits.  See Rule 13d- for other
parties to whom copies are to be sent.

*The  remainder  of this cover  page  shall be filled  out for a  reporting
person's  initial  filing on this  form with  respect  to the  subject  class of
securities,  and for any subsequent amendment containing information which would
alter disclosures provided in a prior cover page.

The  information  required on the remainder of this cover page shall not be
deemed to be "filed"  for the purpose of Section 18 of the  Securities  Exchange
Act of 1934 ("Act") or otherwise  subject to the  liabilities of that section of
the Act but shall be subject to all other  provisions of the Act  (however,  see
the Notes).





                                  SCHEDULE 13D

Item 1.  Security and Issuer

     This Schedule 13D filed by the  Registrants  with the U.S.  Securities  and
Exchange  Commission  on  September  7, 2004 as amended on  September  17, 2004,
November 1, 2004 and November 19, 2004,  relates to the common shares,  $.50 par
value (the "Shares"),  of Mylan  Laboratories  Inc., a Pennsylvania  corporation
(the  "Issuer")  is amended  to furnish  information  as set forth  herein.  All
capitalized  terms not otherwise defined shall have the meaning ascribed to such
terms in the previously filed statement on Schedule 13D.


Item 4.  Purpose of Transaction


     Item 4 is hereby amended to add the following:

     On November 22, 2004,  High River  delivered a letter to the Issuer,  which
letter  is  attached  hereto as  Exhibit  1, and is  incorporated  herein in its
entirety.

     SECURITY  HOLDERS  ARE  ADVISED  TO READ  THE  PROXY  STATEMENT  AND  OTHER
DOCUMENTS  RELATED TO  SOLICITATION  OF PROXIES BY MR. ICAHN AND HIS  AFFILIATES
FROM THE STOCKHOLDERS OF MYLAN  LABORATORIES INC. FOR USE AT ITS SPECIAL MEETING
WHEN  AND  IF  THEY  BECOME  AVAILABLE   BECAUSE  THEY  WILL  CONTAIN  IMPORTANT
INFORMATION.  WHEN COMPLETED,  A DEFINITIVE  PROXY STATEMENT AND A FORM OF PROXY
WILL BE MAILED TO STOCKHOLDERS OF MYLAN  LABORATORIES INC. AND WILL BE AVAILABLE
AT  NO  CHARGE  AT  THE   SECURITIES  AND  EXCHANGE   COMMISSION'S   WEBSITE  AT
HTTP://WWW.SEC.GOV.   INFORMATION  RELATING  TO  THE  PARTICIPANTS  IN  A  PROXY
SOLICITATION  IS  CONTAINED  IN THE  SCHEDULE  14A  FILED BY MR.  ICAHN  AND HIS
AFFILIATES WITH THE SECURITIES AND EXCHANGE  COMMISSION ON OCTOBER 14, 2004 WITH
RESPECT TO MYLAN  LABORATORIES INC. THAT SCHEDULE 14A IS CURRENTLY  AVAILABLE AT
NO CHARGE ON THE SECURITIES AND EXCHANGE COMMISSION'S WEBSITE.


Item 7.  Material to be Filed as Exhibits


1.       Letter dated November 22, 2004 from High River to the Issuer.


SIGNATURE

     After  reasonable  inquiry  and to the  best  of  each  of the  undersigned
knowledge and belief, each of the undersigned certifies that the information set
forth in this statement is true, complete and correct.

Dated:  November 22, 2004

BARBERRY CORP.


By:      /s/ Edward E. Mattner
         Name: Edward E. Mattner
         Title: Authorized Signatory


HOPPER INVESTMENTS LLC
By:      BARBERRY CORP., Sole Member



         By:      /s/ Edward E. Mattner
                  Name: Edward E. Mattner
                  Title: Authorized Signatory


HIGH RIVER LIMITED PARTNERSHIP
By:      HOPPER INVESTMENTS LLC, General Partner
         By:      BARBERRY CORP., Sole Member



                  By:      /s/ Edward E. Mattner
                  Name: Edward E. Mattner
                  Title: Authorized Signatory



/s/ Carl C. Icahn
CARL C. ICAHN


/s/ Gail Golden
GAIL GOLDEN





      [Signature Page of Amendment No. 4 to Schedule 13D with respect to Mylan]
     


                         High River Limited Partnership
                          767 Fifth Avenue - 47th Floor
                            New York, New York 10153


                                                     November 22, 2004


Board of Directors
Mylan Laboratories, Inc.
1500 Corporate Drive - Suite 400
Canonsburg, Pennsylvania  15317-8574

                  Re:  Mylan Laboratories, Inc. ("Mylan")

Ladies and Gentlemen:

     We were astonished to see that within 3 hours after receiving our letter on
November 19, 2005,  Mylan  cavalierly  dismissed  our $20 per share  acquisition
proposal  as a "tactic"  and that less than 3 days after  receiving  our letter,
without  even so much as  placing a phone call to us to  discuss  our  proposal,
Mylan  has  taken  the  position  that  ours is not a  serious  offer  and  that
discussions between our companies are not in the best interest of Mylan.

     We do not, have not and will not make frivolous bids. We advise you that we
anticipate contributing,  together with our affiliates, at least $1.5 billion of
equity to the acquisition of Mylan and are prepared to provide detail  regarding
our financial  condition at your request.  (1) We are in discussion with a major
financial   institution  regarding  additional  funding  and  based  upon  those
conversations  we are confident  that once due diligence is provided we would be
able to submit to the Board a fully  funded  transaction.  Perhaps if the Board,
which has stated that it is in the best  position  to  determine  the  long-term
plans for Mylan,  had  bothered to speak to us rather  than  rushing out a press
release, it could have been better informed before racing to conclusions.

     We think the real test of long-term commitment to a company is reflected by
the number of shares  purchased with your own money.  In our September  meetings
with Mr. Coury he recounted  to us that he was a wealthy  man,  however,  he has
reported purchasing less that 2,000 Mylan shares. Yes, the company has given him
plenty of stock,  but how much of his money has he invested  in Mylan?  How much
have all of the Board members other than Mr. Puskar invested in Mylan?

     It is  interesting  that you have gone back  three to five years to support
the results obtained by Mylan, which you describe as significantly outperforming
"most" industry  peers. We have received a study by A.T.  Kearney that indicates
that for fiscal years 2002-2004,  (years 2003 and 2004 being the "Coury years"),
Mylan's  revenue  and EBITDA  grew at a  compounded  annual  

-------- 
1 Our Mylan position existed prior to our recent  establishment of
a hedge fund and therefore that fund would not participate in this transaction.





growth rate of 11.6 percent and 10.7 percent, respectively,  compared to 21
and 28 percent for its largest competitors.

     Given that performance,  we would have expected Mr. Coury's compensation to
suffer.  However,  paradoxical to what we think would be congruous  compensation
for Mylan  performance,  in the 2003 fiscal year, Mylan paid Mr. Coury over $2.4
million in cash and stock  options  which  Mylan  reported as having a potential
realizable  value of  between  $12.7 and $32.7  million.  In the face of lagging
Mylan performance in the 2004 fiscal year, Mr. Coury was paid over $3 million in
cash  and  received  restricted  stock  which  Mylan  reported  at  a  value  of
$6,150,375.  We find this to be  offensive  and,  given  the fact  that  Mylan's
generic segment revenue  decreased by  approximately  18 percent for the quarter
ending September 30, 2004 over the results for September 30, 2003, it appears to
us that the Board's apparent enthusiasm for existing management is misplaced.

     Although  disappointing,  the substantial  compensation to Mr. Coury is not
surprising,  in  light  of the  criticism  to which  Mylan  has  been  subjected
regarding  corporate  governance.  As reported in the interactive edition of the
Pittsburgh Post-Gazette on November 2, 2004:

          GovernanceMetrics  International,  a New York firm  that  evaluates
 companies on corporate  governance  issues,  ranks Mylan 2.5 on a scale of 1
 to 10, with 10 being the best.  It faulted  the drug maker for  compensation
 practices,  lack of  independent  directors,  and business deals between the
 company and officers,  directors or their  relatives,  said Gavin  Anderson,
 GovernanceMetrics chief executive officer.

          Anderson  cited the $2 million  bonus Coury  received in the fiscal
 year  ended  March  31,  $1.1  million  of which  was  guaranteed.  His firm
 considers  seven of Mylan's 11 directors  non-independent.  Five are current
 or former officers.

          In the face of mounting criticism,  more companies are putting more
 outsiders  on their  boards,  believing  shareholder  interests  are  better
 served if more  directors  have fewer ties with  management.  Charles Elson,
 chairman of the  University  of  Delaware's  Weinberg  Center for  Corporate
 Governance  said  independent  directors  control  75 percent or more of the
 board seats at most companies.

          Mylan  has  "an   exceedingly   high   percentage  of  insiders  or
 quasi-insiders  compared to what's going on inside corporate America today,"
 said Donald Hambrick,  a management  professor at Penn State's Smeal College
 of Business.  "I can see why Icahn is trying to do what he is."

     If your high-speed rejection of our proposal is indicative of what you have
today referred to as the Board's  "considered and careful  judgments when making
any  decisions"  then perhaps we should not be  surprised  either by the matters
referred  to in the above  article  or by the state of  affairs  in which  Mylan
currently finds itself.






                                  Very truly yours,

                                  High River Limited Partnership

                                  By: Hopper Investments LLC,
                                          its general partner

                                  By: Barberry Corp., sole member


                                  By: /s/ Carl C. Icahn
                                  Name: Carl C. Icahn
                                  Title:   Chairman of the Board