Hydra is the largest of the 88 modern constellations, and was one of the 48 constellations cataloged by 2nd century astronomer Ptolemy. Hydra’s head lies at a point about halfway between Procyon in Canis Minor and Regulus in Leo. From there, it snakes (pun intended) south and eastward below Leo and Virgo, sharing two stars with Crater along the way, before ending just below the right scale of Libra. Hydra’s head reaches its highest nightfall ascension in March, but the tail does not reach that point until three months later in June. The best over all view of Hydra is in late April. Hydra is home to three Messier objects: M83 (the Southern Pinwheel Galaxy), M68 (a globular star cluster), and M48 (an open star cluster). http://en.wikipedia.org/wiki/Hydra_(constellation)
Canes Venatici represents the hunting dogs of Bootes, the herdsman. This is a small northern constellation consisting of only two main stars, and it is located below the Big Dipper’s curved handle and to the right of Bootes. Canes Venatici reaches its highest nightfall ascension in May.
In spite of its small size, Canes Venatici is very interesting in its arrangement of galaxies. The Giant Void, the largest galactic supervoid known, exists along side several other notable galaxies. There are four Messier galaxies: M51 (the Whirlpool Galaxy), M63 (the Sunflower Galaxy), M94, and M106. A fifth Messier object in the M3 globular star cluster, which is bright enough to be seen with the unaided eye under a very dark sky. http://en.wikipedia.org/wiki/Canes_Venatici