Hydra was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations defined by the International Astronomical Union. Hydra is the largest of the 88 modern constellations, measuring 1303 square degrees. Also one of the longest at over 100 degrees, its southern end abuts Libra and Centaurus and its northern end borders Cancer. Crater constellation is Latin for cup, and in Greek mythology it is identified with the cup of the god Apollo. Sextans is a minor equatorial constellation which was introduced in 1687 by Johannes Hevelius. Its name is Latin for the astronomical sextant, an instrument that Hevelius made frequent use of in his observations. Felis, Latin for cat, was a constellation created by French astronomer J矇rome Lalande in 1799. It is now obsolete. A Celestial Atlas (1822) by Alexander Jamieson, inspired by the star atlas of Johann Elert Bode, but restricted itself to stars that could be seen with the naked eye. Comprising a systematic display of the heavens in a series of thirty maps illustrated by scientific description of their contents and accompanied by catalogues of the stars and astronomical exercises, plate 26, 1822.