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


                                  SCHEDULE 13G


                    Under the Securities Exchange Act of 1934
                                (Amendment No __)


                    PACIFIC BIOSCIENCES OF CALIFORNIA, INC.
--------------------------------------------------------------------------------
                                (Name of Issuer)


                        Common Stock, $0.0001 par value
--------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                   69404D108
--------------------------------------------------------------------------------
                                 (CUSIP Number)


                                December 31, 2010
--------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)


Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

     [X]    Rule 13d-1(b)
     [ ]    Rule 13d-1(c)
     [ ]    Rule 13d-1(d)

     *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 the disclosures provided in a prior cover page.

     The information required in 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 (the "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).





----------------------------                           -------------------------
CUSIP No. 69404D108              SCHEDULE 13G                 Page 2 of 10 Pages
----------------------------                           -------------------------

--------------------------------------------------------------------------------
    1     Names of Reporting Persons


          Maverick Capital, Ltd. - 75-2482446
--------------------------------------------------------------------------------
    2     Check the Appropriate Box if a Member of a Group (See Instructions)
          (a)  |_|
          (b)  |_|
--------------------------------------------------------------------------------
    3     SEC Use Only

--------------------------------------------------------------------------------
    4     Citizenship or Place of Organization

          Texas
--------------------------------------------------------------------------------
                |   5   |  Sole Voting Power
                |       |
                |       |  3,543,333
                ----------------------------------------------------------------
  Number of     |   6   |  Shared Voting Power
    Shares      |       |
 Beneficially   |       |  0
   Owned by     ----------------------------------------------------------------
    Each        |   7   |  Sole Dispositive Power
  Reporting     |       |
 Person With    |       |  3,543,333
                ----------------------------------------------------------------
                |   8   |  Shared Dispositive Power
                |       |
                |       |  0
--------------------------------------------------------------------------------
    9     Aggregate Amount Beneficially Owned by Each Reporting Person

          3,543,333
--------------------------------------------------------------------------------
   10     Check Box if the Aggregate Amount in Row (9) Excludes
          Certain Shares (See Instructions)                              |_|
--------------------------------------------------------------------------------
   11     Percent of Class Represented in Amount in Row 9

          6.7%
--------------------------------------------------------------------------------
   12     Type of Reporting Person (See Instructions)

          IA
--------------------------------------------------------------------------------





----------------------------                           -------------------------
CUSIP No. 69404D108              SCHEDULE 13G                 Page 3 of 10 Pages
----------------------------                           -------------------------

--------------------------------------------------------------------------------
    1     Names of Reporting Persons


          Maverick Capital Management, LLC - 75-2686461
--------------------------------------------------------------------------------
    2     Check the Appropriate Box if a Member of a Group (See Instructions)
          (a)  |_|
          (b)  |_|
--------------------------------------------------------------------------------
    3     SEC Use Only

--------------------------------------------------------------------------------
    4     Citizenship or Place of Organization

          Texas
--------------------------------------------------------------------------------
                |   5   |  Sole Voting Power
                |       |
                |       |  3,543,333
                ----------------------------------------------------------------
  Number of     |   6   |  Shared Voting Power
    Shares      |       |
 Beneficially   |       |  0
   Owned by     ----------------------------------------------------------------
    Each        |   7   |  Sole Dispositive Power
  Reporting     |       |
 Person With    |       |  3,543,333
                ----------------------------------------------------------------
                |   8   |  Shared Dispositive Power
                |       |
                |       |  0
--------------------------------------------------------------------------------
    9     Aggregate Amount Beneficially Owned by Each Reporting Person

          3,543,333
--------------------------------------------------------------------------------
   10     Check Box if the Aggregate Amount in Row (9) Excludes
          Certain Shares (See Instructions)                              |_|
--------------------------------------------------------------------------------
   11     Percent of Class Represented in Amount in Row 9

          6.7%
--------------------------------------------------------------------------------
   12     Type of Reporting Person (See Instructions)

          HC
--------------------------------------------------------------------------------





----------------------------                           -------------------------
CUSIP No. 69404D108              SCHEDULE 13G                 Page 4 of 10 Pages
----------------------------                           -------------------------

--------------------------------------------------------------------------------
    1     Names of Reporting Persons


          Lee S. Ainslie III
--------------------------------------------------------------------------------
    2     Check the Appropriate Box if a Member of a Group (See Instructions)
          (a)  |_|
          (b)  |_|
--------------------------------------------------------------------------------
    3     SEC Use Only

--------------------------------------------------------------------------------
    4     Citizenship or Place of Organization

          United States
--------------------------------------------------------------------------------
                |   5   |  Sole Voting Power
                |       |
                |       |  3,543,333
                ----------------------------------------------------------------
  Number of     |   6   |  Shared Voting Power
    Shares      |       |
 Beneficially   |       |  0
   Owned by     ----------------------------------------------------------------
    Each        |   7   |  Sole Dispositive Power
  Reporting     |       |
 Person With    |       |  3,543,333
                ----------------------------------------------------------------
                |   8   |  Shared Dispositive Power
                |       |
                |       |  0
--------------------------------------------------------------------------------
    9     Aggregate Amount Beneficially Owned by Each Reporting Person

          3,543,333
--------------------------------------------------------------------------------
   10     Check Box if the Aggregate Amount in Row (9) Excludes
          Certain Shares (See Instructions)                              |_|

--------------------------------------------------------------------------------
   11     Percent of Class Represented in Amount in Row 9

          6.7%
--------------------------------------------------------------------------------
   12     Type of Reporting Person (See Instructions)

          HC
--------------------------------------------------------------------------------





Item 1(a)   Name of Issuer:

            Pacific Biosciences of California, Inc.

Item 1(b)   Address of Issuer's Principal Executive Offices:

            1380 Willow Road
            Menlo Park, California  94025

Item 2(a)   Name of Person Filing:

            This Schedule 13G (the "Schedule 13G") is being filed on behalf of
            each of the following persons (each, a "Reporting Person"):

            (i)   Maverick Capital, Ltd.;
            (ii)  Maverick Capital Management, LLC; and
            (iii) Lee S. Ainslie III ("Mr. Ainslie").

            The Schedule 13G relates to Shares (as defined  herein) held for the
            accounts of Maverick Capital, Ltd.'s clients.

Item 2(b)   Address of Principal Business Office or, if none, Residence:

            The address of the principal business office of (i) Maverick
            Capital, Ltd. and Maverick Capital Management, LLC is 300 Crescent
            Court, 18th Floor, Dallas, Texas 75201, and (ii) Mr. Ainslie is 767
            Fifth Avenue, 11th Floor, New York, New York 10153.

Item 2(c)   Citizenship:

            (i)   Maverick Capital, Ltd. is a Texas limited partnership;
            (ii)  Maverick Capital Management, LLC is a Texas limited liability
                  company; and
            (iii) Mr. Ainslie is a citizen of the United States.

Item 2(d)   Title of Class of Securities:

            Common Stock, $0.0001 par value (the "Shares").

Item 2(e)   CUSIP Number:

            69404D108

Item 3.     If this statement is filed pursuant to ss.ss.240.13d-1(b) or
            240.13d-2(b) or (c), check whether the person filing is a:

   (a)  [ ] Broker or dealer registered under section 15 of the Act (15
            U.S.C. 78o).

                               Page 5 of 10 Pages



   (b)  [ ] Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

   (c)  [ ] Insurance company as defined in section 3(a)(19) of the Act (15
            U.S.C. 78c).

   (d)  [ ] Investment company registered under section 8 of the Investment
            Company Act of 1940 (15 U.S.C. 80a-8).

   (e)  [X] An investment advisor in accordance with ss.240.13d-1(b)(1)(ii)(E).

   (f)  [ ] An employee benefit plan or endowment fund in accordance with
            ss.240.13d-1(b)(1)(ii)(F).

   (g)  [X] A parent holding company or control person in accordance with
            ss.240.13d-1(b)(1)(ii)(G).

   (h)  [ ] A savings association as defined in Section 3(b) of the Federal
            Deposit Insurance Act (12 U.S.C. 1813).

   (i)  [ ] A church plan that is excluded from the definition of an investment
            company under Section 3(c)(14) of the Investment Company Act of 1940
            (15 U.S.C. 80a-3).

   (j)  [ ] A non-U.S. institution in accordance with ss.
            240.13d-1(b)(1)(ii)(J);

   (k)  [ ] Group, in accordance with ss. 240.13d-1(b)(1)(ii)(K).

   If filing as a non-U.S. institution in accordance with
ss.240.13d-1(b)(1)(ii)(J), please specify the type of institution:______________

Item 4      Ownership

            Ownership as of December 31, 2010 is incorporated by reference to
            items (5) - (9) and (11) of the cover page of the Reporting Person.

            Maverick Capital, Ltd. is an investment adviser registered under
            Section 203 of the Investment Advisers Act of 1940 and, as such, may
            be deemed to have beneficial ownership of the Shares which are the
            subject of this filing through the investment discretion it
            exercises over its clients' accounts. Maverick Capital Management,
            LLC is the General Partner of Maverick Capital, Ltd. Mr. Ainslie is
            the manager of Maverick Capital Management, LLC and is granted sole
            investment discretion pursuant to Maverick Capital Management, LLC's
            Regulations.

Item 5      Ownership of Five Percent or Less of a Class

            Not applicable.

Item 6      Ownership of More than Five Percent on Behalf of Another Person.

            Not applicable.

                               Page 6 of 10 Pages





Item 7      Identification and Classification of the Subsidiary Which Acquired
            the Security Being Reported on By the Parent Holding Company or
            Control Person

            Not applicable.

Item 8      Identification and Classification of Members of the Group

            Not applicable.

Item 9      Notice of Dissolution of Group

            Not applicable.

Item 10     Certifications

            By signing below each of the Reporting Persons certifies that, to
            the best of such person's knowledge and belief, the securities
            referred to above were acquired and are held in the ordinary course
            of business and were not acquired and are not held for the purpose
            of or with the effect of changing or influencing the control of the
            issuer of the securities and were not acquired and are not held in
            connection with or as a participant in any transaction having that
            purpose or effect.




                               Page 7 of 10 Pages




                                    SIGNATURE

          After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

Date:  February 14, 2011             MAVERICK CAPITAL, LTD.

                                     By:   Maverick Capital Management, LLC,
                                           Its General Partner

                                           By: Lee S. Ainslie III, Manager

                                               By: /s/ John T. McCafferty
                                                   -----------------------------
                                                   John T. McCafferty
                                                   Under Power of Attorney dated
                                                   February 13, 2003



Date:  February 14, 2011             MAVERICK CAPITAL MANAGEMENT, LLC

                                     By:   Lee S. Ainslie III, Manager

                                           By:  /s/ John T. McCafferty
                                                --------------------------------
                                                John T. McCafferty
                                                Under Power of Attorney dated
                                                February 13, 2003



Date:  February 14, 2011             LEE S. AINSLIE III


                                     By: /s/ John T. McCafferty
                                         ---------------------------------------
                                         John T. McCafferty
                                         Under Power of Attorney dated
                                         February 13, 2003




                               Page 8 of 10 Pages





                                  EXHIBIT INDEX

A.   Joint Filing Agreement, dated February 14, 2011, by and among Maverick
     Capital, Ltd., Maverick Capital Management, LLC, and Lee S. Ainslie III.










                               Page 9 of 10 Pages






                                                                       Exhibit A

                             Joint Filing Agreement

      The undersigned hereby agree that the statement on Schedule 13G with
respect to the Common Stock, $0.0001 par value of Pacific Biosciences of
California, Inc., dated as of February 14, 2011, is, and any amendments thereto
(including amendments on Schedule 13D) signed by each of the undersigned shall
be, filed on behalf of each of us pursuant to and in accordance with the
provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934.



Date: February 14, 2011


                             MAVERICK CAPITAL, LTD.

                              By: Maverick Capital Management, LLC
                                  Its General Partner

                                  By: Lee S. Ainslie III, Manager



                                      By: /s/ John T. McCafferty
                                          ------------------------------
                                          John T. McCafferty
                                          Under Power of Attorney dated
                                          February 13, 2003


                              MAVERICK CAPITAL MANAGEMENT, LLC

                              By: Lee S. Ainslie III, Manager



                                  By: /s/ John T. McCafferty
                                      ----------------------------------
                                      John T. McCafferty
                                      Under Power of Attorney dated
                                      February 13, 2003


                              LEE S. AINSLIE III



                              By: /s/ John T. McCafferty
                                  --------------------------------------
                                  John T. McCafferty
                                  Under Power of Attorney dated
                                  February 13, 2003




                              Page 10 of 10 Pages