Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Canaan VII LP
  2. Issuer Name and Ticker or Trading Symbol
MARINUS PHARMACEUTICALS INC [MRNS]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
285 RIVERSIDE AVENUE, SUITE 250
3. Date of Earliest Transaction (Month/Day/Year)
09/30/2014
(Street)

WESTPORT, CT 06880
4. If Amendment, Date 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
(City)
(State)
(Zip)
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               1,836,398 I See Footnote (1)
Common Stock               2,461,398 I See Footnote (1)

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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 Underlying Securities
(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 of Derivative Security: 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
Stock option (right to buy) $ 6.47 09/30/2014   A   6,000     (2) 09/30/2024 Common Stock 6,000 $ 0 6,000 I By Director

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Canaan VII LP
285 RIVERSIDE AVENUE
SUITE 250
WESTPORT, CT 06880
  X   X    
Canaan Partners VII LLC
285 RIVERSIDE AVENUE
SUITE 250
WESTPORT, CT 06880
  X   X    

Signatures

 Canaan VII L.P. By: Canaan Partners VII LLC its General Partner /s/ Jaime Slocum Attorney-in-Fact   10/02/2014
**Signature of Reporting Person Date

 Canaan Partners VII LLC By: /s/ Jaime Slocum Attorney-in-Fact   10/02/2014
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(1) Shares held directly by Canaan VII L.P. (the "Canaan Fund"). Canaan Partners VII LLC ("Canaan VII") is the sole general partner of the Canaan Fund and each may be deemed to have sole voting, investment and dispositive power with respect to the shares held by the Canaan Fund. Canaan VII disclaims Section 16 beneficial ownership of the securities held by the Canaan Fund, except to the extent of any pecuniary interest therein.
(2) These options were granted to Stephen Bloch, a manager of Canaan VII and a vice president of Canaan Management, Inc. ("Canaan Management," and together with Canaan VII and the Canaan Fund, the "Canaan Entities") who serves as the representative of the Canaan Entities on the Issuer's board of directors. Options to purchase 1,000 shares became exercisable on the date of grant and the remaining 5,000 shares become exercisable in ten installments of 500 shares each on the last day of each of the ten months succeeding the grant date. Dr. Bloch, pursuant to arrangements with Canaan VII and Canaan Management, is contractually obligated to assign the value of any remuneration received for service as a director. Each of the Canaan Entities disclaims beneficial ownership in the stock options held by Dr. Bloch and shares exercisable therefrom, except to the extent, if any, of its pecuniary interest therein.

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