The article focuses on particular problems that arose during work on a new edition of the Old Church Slavonic (OCS) Pentateuch preserved in Croatian Glagolitic breviaries and missals. It describes the peculiarities of the material in the Book of Genesis as attested in pre-15th century breviaries. The article provides specific examples of passages in which the Old Testament (OT) text of the Pentateuch was not included in the Slavonic Prophetologia, which contained the earliest preserved OCS translation of OT texts. These consist of (1) abridged OT genealogies that had to be shortened in the breviaries; (2) abridged non-Prophetologion passages included in breviaries in the shortened redaction; (3) unabridged non-Prophetologion passages for which a new, ad hoc translation was included in the breviaries. The article offers several examples of the breviary text as it will appear in the forthcoming edition. It presents the edition of the text with variant readings from all available manuscripts.