In the second half of the XXth century Semiotics emerges as an autonomous field of research among the disciplines of language and culture. Here we deal with a particular phenomenon: the contemporary establishing of a semiotic terminology, a scientific metalanguage and a new field of research. The analysis of some linguistic objects we have called semiological tools can highlight the epistemological issues explaining the relationship between terminology and metalanguage concerned in the process of institutionalisation of this new field of research. This relationship can also explain some basic differences between two important directions in Semiotics, revealing themselves in the textual architecture of the selected linguistic objects. Then we have analysed the two tomes of Sémiotique. Dictionnaire raisonné de la théorie du langage edited by Greimas and Courtés (1979, 1986) and the Encyclopedic Dictionnary of Semiotics edited by Sebeok (1986). Discussing their textual architecture and their terminology we can finally identify two different epistemological models we have defined respectively the circle and the spiral.