In the Bibliothèque Municipale in Troyes, France, ms. 1897 is entitled “Vetus Eucologium”  This is a Book of Hours (‘Heures à l’usage de Meaux’), was written partly in Latin and partly in French and is dated towards the end of the 15th century; it may have originated in Paris.
On folio 48v in the border at left-hand, a somewhat stylised dextral snail may be seen, the head of the animal with two tentacles, an eye-spot, nostrils and the mouth closed; where it a human, it seems incontent with the situation. The coloration of the shell reminds me of a Cepaea-like garden snail.
 Troyes BM, ms. 1897, 128 ff. http://bit.ly/1jYMAA9 (21.ii.2014).