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 *
Bloch Stephen M
   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 _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O CANAAN VII L.P., 285 RIVERSIDE AVENUE SUITE 250		 3. Date of Earliest Transaction (Month/Day/Year)
09/24/2015
(Street)

WESTPORT, CT 06880		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ 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 09/28/2015   M   12,515 A $ 1.04 12,515 D  
Common Stock 09/28/2015   M   27,035 A $ 1.04 39,550 D  
Common Stock               1,836,398 I See Footnote (1) (2)
Common Stock               2,461,398 I See Footnote (1) (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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) $ 12.98 09/24/2015   A   6,300     (3) 09/24/2025 Common Stock 6,300 $ 0 6,300 D  
Stock option (right to buy) $ 1.04 09/28/2015   M     12,515   (4) 06/09/2019 Common Stock 12,515 $ 0 0 D  
Stock option (right to buy) $ 1.04 09/28/2015   M     27,035   (5) 03/20/2022 Common Stock 27,035 $ 0 0 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Bloch Stephen M
C/O CANAAN VII L.P.
285 RIVERSIDE AVENUE SUITE 250
WESTPORT, CT 06880		   X      

Signatures

 /s/ Jaime Slocum, Attorney-in-Fact   09/28/2015
**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" and together with the Canaan Fund, the "Canaan Entities") 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. Stephen Bloch, a manager of the Canaan Fund, serves as the representative of the Canaan Entities on the Issuer's board of directors.
(2) Dr. Bloch disclaims beneficial ownership over the securities owned by the Canaan Fund, and this report shall not be deemed an admission that such reporting person is the beneficial owner of such shares, except to the extent of his pecuniary interest, if any, in the securities by virtue of the limited liability company interests he owns in Canaan VII, the general partner of the Canaan Fund.
(3) 1,050 options vest on September 30, 2015 and the remaining options vest on the last day of the month in 10 equal monthly installments commencing 10/31/2015.
(4) 25% vested on 6/9/09; remaining shares vested in equal installments at the end of each of the 36 months after 6/9/09. These options were granted by the Issuer prior to Dr. Bloch becoming a manager of the Canaan Fund.
(5) 100% vested on 3/20/13. These options were granted by the Issuer prior to Dr. Bloch becoming a manager of the Canaan Fund.

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