A piece of a Roman mosaic was called a tessera.
Taking as a starting-point the wide archenteric cavity which the medusa inherits primitively from the antecedent actinula-stage (see article Medusa), we find, in such a form as Tessera, four interradial areas of concrescence between the exumbral and subumbral layers of endoderm, four so-called septal nodes or " cathammata," subdividing the stomach into four wide, radially situated pouches which communicate with each other beyond the septal nodes by wide apertures constituting what is termed by courtesy a ring-canal.
The use of writing for the purpose of the token between " guest-friends " (tessera hospitalis) is certainly very ancient.
Tessera is a line of mosaic tiles that are cast in more than 40 iridescent and non-iridescent colors, as well as blends and patterns that can be customized.
The Marco Polo Airport is at Tessera (linked by bus).