Among these are dolphins, sea cows, sharks, seals, rays, boas, jellyfishes and penguins. Some wide tanks host dolphins, sharks, seals, manatees, turtles and jellyfishes. Crown jellyfishes are the six families of true jellyfish that belong to the order Coronatae. This unicellular organism settles in the tissue of jellyfishes. The Jellies Exhibit, a separate attraction hosts jellyfishes. One of jellyfishes stings Shinichiro, rendering him unconscious. These jellyfishes are notorious for the large swarms they form in the summertime. Staurozoa is a class of Medusozoa, jellyfishes and hydrozoans. Chirodropida is an order of box jellyfishes. The biology and ecology of the mesobathypelagic jellyfishes is poorly known. The bell is a more "boxy" shape than that of the umbrella-like true jellyfishes. Pelagia is a genus of jellyfishes in the family Pelagiidae. Jellyfishes with stinging tentacles are usually hunters. At the moment, many seafishes inhabit the area, including jellyfishes. In 1946, Reg Sprigg noticed "jellyfishes" in rocks from Australia's Ediacara Hills.