Taurus Poniatovii (Latin for Poniatowski's bull) was a constellation created by Martin Poczobut in 1777 to honor Stanislaus Poniatowski, king of Poland. It was located in the north-eastern corner of Ophiuchus. It is no longer in use.
Telescopium Herschelii (Latin for Herschel's telescope) was a constellation created by Maximilian Hell in 1781 to honor the famous English astronomer Sir William Herschel. It was located between the constellations of Lynx and Gemini. It is no longer in use.
Triangulum Minor or Triangulum Minus (Latin for lesser triangle) was a constellation created by Hevelius. It was formed from the southern parts of Triangulum. It is no longer in use.
Turdus Solitarius (Latin for solitary thrush) was a constellation created by Pierre Charles Lemonnier in 1776 from stars of Hydra's tail. It was replaced by another constellation, Noctua (the Owl). Neither of these constellations are in use anymore.
Vespa (Latin for wasp) was a constellation created by Jakob Bartsch in the 17th century. It was located between the constellations of Aries and Perseus. It was later recognized as Musca Borealis before returning to Aries.