MEDUSA. 274 MEEHAN. Rfe^tV) ■4. 8TROB1LA OF Au- relia Savidula. cles; in this stage it remains about eighteen months. Toward the end of this period the body increases in size and divides into a series of cup- shaped disks. These saucer-like disks are scal- loped on the upturned eilge. tentacles lead out, and the animal assumes the Strobila stage ( Fig. 4). Finally the disks separate, the upper one becomes detached and with the other disks swims away in the Ephyra form (Fig. 5). When about a fifth of an inch in diameter, and toward the middle or end of the summer, this young medusa becomes an adult Aurclia. Other forms of greater beauty occur in the Medi- terranean and the tropics. A much larger kind of medusa than Aurclia, Vyanea arctica, is connuon on the (ivand Banks and olV the coast of Xorlhern New Kngland. It sometimes attains a diam- eter across the disk of from three to even five feet, though it is produced from a Scyphistoma not more than half an inch in height. Its tentacles stream behind, sometimes to the length of several fathoms, ami poison the hands of fishermen. Spe- Fia. 5. EPHYiiA OK EAK- cics of Pclagia do not un- UE8TKKKEUO.NI.ITIO.V ^j.^,,,, .,„ alteration of gen- OF All relia. (After f. , n Agassis.) erations (see Faktiieno- GEXEsis), but grow directly from the egg, without passing through a Strobila stage. For various Mediterranean and tropical forms, see Colored Plate of Medv.s.e and Sipiionopiiore. Medusa? shelter various kinds of animals, which live as fellow-boarders or commensals, viz. tem- porary non-attached ]iarasitcs. Some of them live in or under the mouth-cavity or between the four tentacles of the larger mcdisa~. Such is the little am[>hipod crustacean, llyperia, which lives within the mouth, while small fishes, such as the butterflsh, swim under the umbrella of the larger jelly-lishes, C'yanca. etc.. for shelter and protec- tion. Besiiles small animals of various classes, the larger jelly-fishes kill by means of their net- tling organs small cuttle-fishes and true fishes, the animals being paralyzed by the ])ricks of the minute barbed darts. See Ccelenterata ; C'tenopiiora : Nematocy.st. Fo.ssiL JIeiiis.t:. Beoause of the jelly-like nature of the body and the absence of any hard parts in medusa', these animals would seem to present the inii«t unfavorable conditions for fos- silization. Indeed, they are rarely found in the ancient rocks, but there are some noteworthy ex- ceptions, especially in the fainbrian and .Tiirassic formations. Impressions and also what have hern considered to be casts of the medusoid bodies have been fnund in rocks of the Lower Cambrian in both Sweden and North America. The ]ieeuliar fossil called Pactyloidiles fnund in the green roofing slates of Oranville. Washington Count.v, N. Y., is generally regarded as of this nature. Fine impressions of jelly-fish are found in the surfaces of the fine-grained lithographic lime- stones of Jurassic age at Solcnhofen and other places in Bavaria. (.'onsult: Agassiz, L., Contributions to tli0 yuturul lliistori) of the United States, vols, iii., iv. (Boston, 1802-00) ; Agassiz. A., .Vo;//i Aiiur- icuii Aculviihs (Cambridge, KSOo) ; llaeckel. .Si/s- tem dcr Mcdusen (Jena, 1880-81); id., "Keport on Medusic," in Chulleiiger llcports, vol. iv. ( Lon- don, 1881) ; id., '•Ueber fossile Medusen,"' in Xcitschrift fur cissenschu{lli<:he Zoulvjic, vols. XV. and xix. (Leipzig, 180.5-70) ; Von Amnion. '"L'eber jurassische iledusen," in AhhntidluiifUfi dcr Kijiii<ilicl'. biiicriachcn Akadcmic dcr lli.s- sc}iscliaflr)i. vol. xvii. (Munich. ISS:?) : Walcntt. ■"Fossil Medus.T," in Monoi/rtiplis of the United States Geological Hiirreu. vol. xx.x. (Washington, 1898). SeeHYDROli); Hydkozoa. MEDUSA KONDANINI, rAn'da-ne'nf. A noted marble, formerly in the Rondanini Palace in Uome, acquired in 1808 by the Crown Prince of Bavaria, and now preserved in the (Jlyptothek at Munich. It is of the later type which repre- sents the (iorgon not with convulsed features, but with a fixed and calm expression. MEDUSE, mu'dyz'. La (Fr., the Medusa). A French vessel sent by the Government to resume possession of the colony of Senegal, which had been restored by the treaties of 181.>. She was wrecked near the .frican coast on July '2, 1816, and 140 persons took refuge on a hastily con- structed raft. After twelve days of horrible suti'ering, during which the castaways were re- duced to eating their companions, the fifteen survivors were rescued by the brig Argus. The disaster forms the subject of a famous painting by Gericault, in the Louvre, exhibited in the Salon of 1810. The picture represents the raft just as the brig appears on the horizon, and is notable for its intense realism. MED'WIN, Thomas (1788-1809). The bio|p- rapher of the poet Shelley, born at Horsham, in Sussex, England, March 20, 1788. His mother, Mary, a daughter of .Tohn Pilfold, was first cousin to Klizabeth Pilfold. the mother of Shelley. Jledwin and Shelley were eilucated at Sion House .'school. Brentford, and they spent their vacations together at Horsham. Medwin entered the army, and became a lieutenant in 181.'?. With his regi- ment he passed some time in India. In ISl!) he retired on half pay and soon (piitted the service. In 1821 he went to Italy, where he associated intimately with Shelley and Lord Byron. He afterwards led an unsettled life. He died at Horsham, August 2, 1800. His Journal of the Comersatinnn of Lord Hgron (1824) created a sensation owing to its personalities. . Memoir of Shrllei/ (1833) was afterwards expanded into The Life of Shelley (2 vols., 1847). MEEHAN. mr-'on. Thomas (1820-1001). An American botanist and horticulturist, born at Potter's liar, near Loiulon. In 1847 he came to .merica to manage Buist's nursery at Rosedale, ne.ir Philadelphia, and six years later started his own mirseries at Oermantown. Meehan was prominent in Philadelphia, as a member of the council and 'father of the small parks." As a vegetable biologist he obtained great fame, espe- cially by his theory that sex is determined by the vitality of the branch bearing the llower. A member of the Philadelphia .cademy of Natural Sciences and of the American Association for the
