SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* M/C VENTURE PARTNERS VI L P (Last) (First) (Middle) C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 (Street) BOSTON MA 02109 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 10/16/2014	3. Issuer Name and Ticker or Trading Symbol Zayo Group Holdings, Inc. [ ZAYO ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. 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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	25,437,645	I	See Footnotes(1)(2)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* M/C VENTURE PARTNERS VI L P (Last) (First) (Middle) C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 (Street) BOSTON MA 02109 (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* M/C Venture Partners, LLC (Last) (First) (Middle) C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 (Street) BOSTON MA 02109 (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* M/C VP VI, L.P. (Last) (First) (Middle) C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 (Street) BOSTON MA 02109 (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* M/C Venture Investors LLC (Last) (First) (Middle) C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 (Street) BOSTON MA 02109 (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* M/C Venture Partners V, L.P. (Last) (First) (Middle) C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 (Street) BOSTON MA 02109 (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* M/C VP V, LLC (Last) (First) (Middle) C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 (Street) BOSTON MA 02109 (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* Chestnut Venture Partners LP (Last) (First) (Middle) C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 (Street) BOSTON MA 02109 (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* Chestnut Street Partners Inc (Last) (First) (Middle) C/O M/C PARTNERS 75 STATE STREET, SUITE 2500 (Street) BOSTON MA 02109 (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. Consists of (i) 24,160,854 shares held of record by M/C Venture Partners VI, L.P., (ii) 757,871 shares held of record by M/C Venture Investors L.L.C., (iii) 497,320 shares held of record by M/C Venture Partners V, L.P. and (iv) 21,600 shares held of record by Chestnut Venture Partners, L.P. (together, the "M/C Shareholders"). M/C VP VI, L.P. is the sole general partner of M/C Venture Partners VI, L.P. and M/C Venture Partners, LLC is the sole general partner of M/C VP VI, L.P. M/C VP V LLC is the sole general partner of M/C Venture Partners V, L.P. (continued)

2. Chestnut Street Partners, Inc. is the sole general partner of Chestnut Venture Partners, L.P. As the Managers of M/C Venture Partners, LLC, M/C Venture Investors L.L.C. and M/C VP V LLC, Gillis S. Cashman, Brian M. Clark, David D. Croll, James F. Wade and John W. Watkins collectively have direct or indirect investment and voting authority over the securities held by M/C Venture Partners VI, L.P., M/C Venture Investors L.L.C. and M/C Venture Partners V, L.P. David D. Croll and James F. Wade collectively have investment and voting authority over the securities held by Chestnut Venture Partners, L.P. Each of the foregoing entities and individuals disclaims beneficial ownership of the shares held of record by the M/C Shareholders, except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for purposes of Section 16 or for any other purpose. (continued from footnote 1)

Remarks:

	M/C VENTURE PARTNERS VI, L.P., By: M/C VP VI, LLC, its general partner, By: M/C Venture Partners, LLC, its general partner, By: /s/ Gillis S. Cashman, Manager	10/16/2014
	M/C VP VI, LLC, By: M/C Venture Partners, LLC, its general partner, By: /s/ Gillis S. Cashman, Manager	10/16/2014
	M/C VENTURE PARTNERS, LLC, By: /s/ Gillis S. Cashman, Manager	10/16/2014
	M/C VENTURE INVESTORS, L.L.C., By: /s/ Gillis S. Cashman, Manager	10/16/2014
	M/C VENTURE PARTNERS V, L.P., By: M/C VP V, LLC, its general partner, By: /s/ Gillis S. Cashman, Manager	10/16/2014
	M/C VP V, LLC, By: /s/ Gillis S. Cashman, Manager	10/16/2014
	CHESTNUT VENTURE PARTNERS, L.P., By: Chestnut Street Partners, Inc., its general partner, By: /s/ David D. Croll, President	10/16/2014
	CHESTNUT STREET PARTNERS, INC., By: /s/ David D. Croll, President	10/16/2014
	** Signature of Reporting Person	Date
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