Agar. Agar or agar-agar is a gelatinous substance derived by boiling a polysaccharide in red algae, where it accumulates in the cell walls of agarophyte and serves as the primary structural support for the algae's cell walls.gar. Agar or agar-agar is a gelatinous substance derived by boiling a polysaccharide in red algae, where it accumulates in the cell walls of agarophyte and serves as the primary structural support for the algae's cell walls.
Photo by Lisa Powers. Description: Typical timber rattlesnakes measure anywhere from 36-58 inches (91-147 cm) in length with Klauber (1956) reporting the largest timber rattlesnake ever recorded to be 74  inches (189.23 cm) collected near New Orleans, LA in the 1940s. Timber rattlesnakes are the 2nd largest venomous snake found in the eastern United States.
Appearance. The timber rattlesnake (Croatus horridus) is the largest of the three species of venomous snakes found in Pennsylvania (the other two venomous species are the northern copperhead and the endangered Massasauga rattlesnake).n northern portions of their distribution, timber rattlesnakes are most commonly found in mountainous areas in which there are numerous rocks and rock crevices or in dense, thick mixed forest sites. In the southern portions of their distribution, timber rattlesnakes are often found in swampy, marshy habitats.