The selectmen of each town in which places have been designated in its navigable waters for planting or cultivating oysters, clams or mussels shall provide a book, to be kept by the town clerk, for recording all applications for such places, together with the written designation and descriptions of the places designated and set out thereon, and all assignments of such places. The town clerk shall record each application and note thereon the day when it was received for record and the book and page where it was recorded and make an alphabetical index of all such applications, designations and assignments, specifying the names of the applicants and of the assignors and assignees, separately; and an attested copy of any such application, designation or assignment, with a certificate that it has been recorded, shall be conclusive evidence of the fact of such record and prima facie evidence of the validity of such application, designation or assignment.