The “Missale praecipuorum festorum” is a manuscript in the Bibliothèque Interuniversitaire de Montpellier. It is date to the 14th century and the description reads: “Missal festive as indicated in the title; reserved for important holidays of the year, hence its rich ornamentation. Missing is the Sanctus, the Te Igitur and the first prayers of the consecration Canon. Beginning of each Mass in small characters, the most important after the first psalm, except f.13v, which is in higher type than other folios (beginning of the Canon of the Mass). Textura. No corrections or marginal annotations, except f. 13 prayer added later in a bastard writing” .
On f. 03v in the left margin a stylised snail is shown. The shell is sinistral, with the aperture extending the last whorl. The animal has two large (and two small) tentacles, with an eye-spot.
Folio 21v shows a similar snail. Here the shell is dextral and seemingly ribbed. The animal has four tentacles (two large, two small) and is humanised.
 BIM Ms. H 261, 30 ff. http://www.calames.abes.fr/pub/ms/D01041364.