The book of today’s post is an incunable from the Bayerischen Staatssammlung, München. It was issued in 1499 in Strassburg and is a German translation, entitled “Von der erfarün[g] des strengen Ritter[s] johannes van montauille”, of the work of Jean de Mandeville . A book account of his supposed travels, which probably first appeared in Anglo-Norman French, and first circulated between 1357 and 1371. By aid of translations into many other languages it acquired extraordinary popularity. Despite the extremely unreliable and often fantastical nature of the travels it describes, it was used as a work of reference.  The illustrations in this German copy were made by an anonymous artist.
On this page (f. 39v) one of the illustrations shows undoubtedly a snail. The shell, which is drawn with much fantasy, may be considered dextral. The animal has two tentacles and an eye. This imaginary – at least deformed – snail is said to be very large. Perhaps a link to the ‘large snail theme’ we have seen before?
 BSB, Ink. M-102, 70 ff. urn:nbn:de:bvb:12-bsb00029982-4
 http://en.wikipedia.org/wiki/John_Mandeville, where also more background information on this work may be found.