FranceThe archaeological research carried out on the site of Saint Peter's monastery in Osor (Island of Cres, Croatia), has recently revealed a small building interpreted as a mausoleum. A distinctive feature of this building is that it contains masonry tombs built prior to its construction, and as a consequence arranged in a regular manner, which have been defined under the term formae. The rareness of this type of funerary installation -according to the inventories -in the Dalmatian Adriatic area, forces us to question its presence in this particular context. In addition, apart from the primary study of the monument itself, the presence of the formae provides us with the opportunity to ask a more general question as to the use of this particular funerary package by looking at discoveries elsewhere in Europe, both historically and more recently, with the aim of providing a comparative study. Through this initial overview we hope, therefore, to determine whether there exists a set body of characteristics, indicative of this mode of inhumation, particularly in terms of dating and use.