This Scyphomedusa has a saucer-shaped bell up to 2 m in diameter at high latitudes; more southern specimens such as those near Rosario are usually closer to 50 cm. The bell has a thick center and a thinner margin. The margin is divided into 8 pairs of thick lobes (for a total of 16 lobes) (photo). Has 8 clusters of up to 150 highly extensible tentacles arranged in several rows, arising from horseshoe shaped regions between the lobes (photo). Has 8 rhopalia, each of which is situated between the two lobes of a pair (photo). Oral arms highly folded, forming a blocky mass only about as long as the bell is wide (but see this photo for extended oral arms). Color deep brick red to purplish, rose, violet, or even milky white. Yellowish-brown in small specimens, often more red in large individuals. The swimming medusa looks like an 8 pointed star at the end of its power stroke. The tentacles may trail down as far as 9 m in large specimens, 2 m in the 50 cm individuals found in our area.