“Horae ad usum Parisiensem” is the name of one of the manuscripts in the collection of Bibliothèque National, Paris. It originated from the 15th century .
As usual the Book of Hours starts with a calender, here in French. On folio 5r, for May, we see the first snail in the lower left corner. A bird (duck or swan) is eating the snail. The sinistral shell has regularly coiling whorls.
The second snail is on folio 8r, for August. The right-upper corner shows a hybrid with a sinistral shell is his hands, the snail stretching out and its two tentacles are partly outside the border.
On folio 28v another sinistral snail is found, the animal with an eye-spot and two tentacles.
The other occurrences are in the part “Heures de la Vierge” [Hours of the Virgin]. Folio 33r, lower left corner, has another sinistral snail. The shell has here slightly more whorls and the aperture is relatively wide. The animal has two tentacles.
Folio 58v has a similar snail in the lower border, with a bird (Eurasian Jay?) looking very interested.
Finally there is one on folio 71r. Here the snail is in the left-hand border, it is a dextral specimen.
All snail are quite stylised and shown in ‘2D squashed‘ mode.