Despite a worldwide moratorium on using mermaids as bait, countries like Norway, Iceland, and Japan take advantage of loopholes and "scientific mermaid bait programs" to justify their use of these endangered creatures.  From St. Nicholas magazine, 1908.

Here's the Old Witch of the Sea from The Story of the Mermaiden, Adapted from the German of Hans Anderson by E. Ashe and illustrated by Laura Troubridge, 1888.

From Histoire d'Angleterre by Prudence Guillaume de Roujoux, 1844.

From A River Holiday, written and illustrated by Harry Furniss, 1883.

The Story of the Mermaiden, Adapted from the German of Hans Anderson by E. Ashe and illustrated by Laura Troubridge, 1888.

From The Blue Poetry Book by Andrew Lang and illustrated by Lancelot Speed, 1891.

The Siren of Warmington by John Collett and illustrated by Lancelot Speed, 1889.

"A commonplace amphibious young person, with no ideas beyond not dressing herself."  From In the Green Park; or, Half-pay Deities by F. Norreys Connell, 1894.

Everyone called a different question to the parrot, from The Bookshelf for Boys and Girls: Little Journeys into Bookland, 1912.  [For Gary Barwin.]

A deep-sea diver encounters a thriving community of merfolk, from Punch, 1866.

A mermaid, or technically "a wriggler sarpint of old Nile" [sic], from Punch, 1892.

How is a paint-worthy subject like an airpane exit hatch?  Sometimes the nearest one is behind you.  In this illustration by Frank Haviland for The Bystander (1906), the artist is blissfully unaware that he has a half-human sea creature for a critic.

These mermaids appear in Punch, 1899.

An illustration from an 1889 issue of Puck magazine.