^C. arctica^, the sun-jelly or sea-blubber. This is the largest jellyfish known. Some individuals measure seven and a half feet across the disk and have tentacles more than one hundred feet long. Usually they are three to five feet in diameter, with tentacles thirty to forty feet long. The disk is red, the margin white and scalloped. The tentacles, of different colors, are covered with lasso- or stinging-cells, and are arranged in eight distinct, thick clusters on the margin. From the mouth hang four long and very broad, thin curtains, much folded and ruffled, whose edges at times look as if they were embroidered, because great numbers of discharged eggs are attached to them. Four egg-sacs hang from the disk near the manubrium, and eight sense-organs (tentaculocysts), in hardened coverings, lie in some of the deep incisions of the margin. /Cyanea/ [pg139] is usually solitary, seldom being seen in company with others. It is common on the New England coast, and is frequently found stranded on the beach, where it in no way suggests the beautiful appearance it presents when floating in the water. Like /Aurelia/, /Cyanea/ has a strobila stage. It is supposed that the young remain near the bottom, for they are seldom seen, while adults are plentiful. They begin to appear in numbers at the end of summer from Cape Cod northward. ^C. fulva.^ This species is found in midsummer south of Cape Cod and is common in Long Island Sound. Its general color is light yellowish-brown, the flowing curtains being the darkest part of the animal. It is not as large as C. arctica, and the lobes of the margin are deeper and more rounded. ^C. versicolor.^ The whole disk is bluish milky-white, the flowing curtains are light brown, and the tentacles are pink. It is not so large as /C. arctica/. Found in the spring on the southern coast. [Illustration: /Linerges mercurius/, thimble-fish.] GENUS ^Linerges^ ^L. mercurius^, the thimble-fish. The English name indicates the form as well as the size of this little brownish jellyfish, which is found near the Florida Keys, extending in lines for considerable distances. GENUS ^Pelagia^ ^P. cyanella.^ Umbrella spherical, margin scalloped, tentacles eight in number; four long appendages ruffled on the edges hang from the mouth; size about two inches in diameter; appendages four inches long; color pink. (See next page.) SUBORDER ~RHIZOSTOMÆ~