It's probably the extracted civil record you have from FamilySearch - here. These are extracts from the civil records, but leave out some of the details noted in the GRO register.
Ballyconnell Chapel is in Co. Wicklow and in the townland of the same name and was one of the chapels for Clonmore parish, which covered parts of counties Wicklow and Carlow.
The extracted record, mentioned above, includes a reference to the register page, the 'Reference ID 944' and this allow a search for the matching BMD index details. The following record matches for the groom based on name, year, area and page number :
Name : Peter Tracy
Event Type : Marriage
Year : 1864
Registration District : Shillelagh
Volume 17 / Page 944
A 'Margret Smyth' appears with the same references so a cross-match. You can use these references to order a research cert costing €4, which will include the additional details I mentioned (I've attached notes on how to do this below), Records for the Catholic parish of Clonmore are included on RootsIreland pay-website, but note that a parish marriage record may not include as much detail as the civil record you can get from the GRO.
To order GRO research certs - download the order form from this link (MSWord document, Dept.of Social Protection or Welfare),
Print out a copy and enter your details in section 1, and your credit card details in section 3. Put the index references for the record you wish to order (name, record type, reg. district, record type, year/quarter, page & volume) in section 2. If you have several certs to order, you can print the references for these on a separate page and attach to the order form.
Ignore the irrelevant sections on the form such as exact date of birth etc, PPS number etc, the forms are more geared to modern official certs for legal purposes. In section 3 tick the 'photocopy' option to select the cheaper research certs. Post (or fax) the completed form to the GRO, the head office address is at the top of the form.
Certs are normally delivered by post, but you can opt for delivery by email by ticking the option in section 1 and including an email address.
