SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* ATLAS VENTURE FUND V LP (Last) (First) (Middle) C/O ATLAS VENTURE 890 WINTER STREET, SUITE 320 (Street) WALTHAM MA 02451 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol MOMENTA PHARMACEUTICALS INC [ MNTA ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 06/21/2004
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	06/21/2004		P		38,575	A	$6.5	38,575	I	See Footnote(1)
Common Stock	06/21/2004		P		4,791	A	$6.5	4,791	I	See Footnote(2)
Common Stock	06/21/2004		P		4,791	A	$6.5	4,791	I	See Footnote(3)
Common Stock	06/21/2004		P		642	A	$6.5	642	I	See Footnote(4)
Common Stock	06/21/2004		P		69,789	A	$6.5	69,789	I	See Footnote(5)
Common Stock	06/21/2004		P		1,278	A	$6.5	1,278	I	See Footnote(6)
Common Stock	06/21/2004		P		2,134	A	$6.5	2,134	I	See Footnote(7)
Common Stock	06/21/2004		P		48,799	A	$6.5	48,799	I	See Footnote(8)
Common Stock	06/21/2004		P		73,201	A	$6.5	73,201	I	See Footnote(9)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* ATLAS VENTURE FUND V LP (Last) (First) (Middle) C/O ATLAS VENTURE 890 WINTER STREET, SUITE 320 (Street) WALTHAM MA 02451 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ATLAS VENTURE PARALLEL FUND V-A C V (Last) (First) (Middle) C/O ATLAS VENTURE 890 WINTER STREET, SUITE 320 (Street) WALTHAM MA 02451 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ATLAS VENTURE PARALLEL FUND V-B C V (Last) (First) (Middle) C/O ATLAS VENTURE 890 WINTER STREET, SUITE 320 (Street) WALTHAM MA 02451 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ATLAS VENTURE ENTREPRENEURS FUND V LP (Last) (First) (Middle) C/O ATLAS VENTURE 890 WINTER STREET, SUITE 320 (Street) WALTHAM MA 02451 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ATLAS VENTURE FUND VI LP (Last) (First) (Middle) C/O ATLAS VENTURE 890 WINTER STREET, SUITE 320 (Street) WALTHAM MA 02451 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Atlas Venture Fund VI GmbH & Co KG (Last) (First) (Middle) C/O ATLAS VENTURE 890 WINTER STREET, SUITE 320 (Street) WALTHAM MA 02451 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ATLAS VENTURE ENTREPRENEURS FUND VI LP (Last) (First) (Middle) C/O ATLAS VENTURE 890 WINTER STREET, SUITE 320 (Street) WALTHAM MA 02451 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ATLAS VENTURE ASSOCIATES V LP (Last) (First) (Middle) C/O ATLAS VENTURE 890 WINTER STREET, SUITE 320 (Street) WALTHAM MA 02451 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Atlas Venture Associates VI, L.P. (Last) (First) (Middle) C/O ATLAS VENTURE 890 WINTER STREET, SUITE 320 (Street) WALTHAM MA 02451 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. These shares were purchased directly by Atlas Venture Fund V, L.P.

2. These shares were purchased directly by Atlas Venture Parallel Fund V-A, C.V.

3. These shares were purchased directly by Atlas Venture Parallel Fund V-B, C.V.

4. These shares were purchased directly by Atlas Venture Entrepreneurs' Fund V, L.P.

5. These shares were purchased directly by Atlas Venture Fund VI, L.P.

6. These shares were purchased directly by Atlas Venture Fund VI GmbH & Co. KG.

7. These shares were purchased directly by Atlas Venture Entrepreneurs' Fund VI, L.P.

8. These shares were purchased directly by Atlas Venture Fund V, L.P., Atlas Venture Parallel Fund V-A, C.V., Atlas Venture Parallel Fund V-B, C.V. and Atlas Venture Entrepreneurs' Fund V, L.P., each of which Atlas Venture Associates V, L.P. is the General Partner. Atlas Venture Associates V, L.P. disclaims beneficial ownership of such shares except to the extent of its pecuniary interest therein.

9. These shares were purchased directly by Atlas Venture Fund VI, L.P., Atlas Venture Fund VI GmbH & Co. KG and Atlas Venture Entrepreneurs' Fund VI, L.P., each of which Atlas Venture Associates VI, L.P. is the General Partner. Atlas Venture Associates VI, L.P. disclaims beneficial ownership of such shares except to the extent of its pecuniary interest therein.

	Atlas Venture Fund V, L.P.	06/24/2004
	Atlas Venture Parallel Fund V-A, C.V.	06/24/2004
	Atlas Venture Parallel Fund V-B, C.V.	06/24/2004
	Atlas Venture Entrepreneurs' Fund V, L.P.	06/24/2004
	Atlas Venture Fund VI, L.P.	06/24/2004
	Atlas Venture Fund VI GmbH & Co. KG	06/24/2004
	Atlas Venture Entrepreneurs' Fund VI, L.P.	06/24/2004
	Atlas Venture Associates V, L.P.	06/24/2004
	Atlas Venture Associates VI, L.P.	06/24/2004
	/s/ Jeanne Larkin Henry (Vice-President)	06/24/2004
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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