| Description | English: Two-tailed mermaid used as printer’s mark by the heirs of Petrus Ravanus in Venice |
| Date | 1550 |
| Source | Grammaticae institutiones (https://archive.org/details/bub_gb_fFJHW0aDyzQC/page/n697/mode/2up) |
| Author | Anonymous |
Two-Tailed Mermaid or Siren