CTENACODON. 640 CUBA. Plagiaulax and Polyniastodon from the Eocene, aiul other Mesozoic and Tertiary genera, are in- cluded as a subchiss. Prototheria; a group sliowing atfinities to the marsupials among the nu'tatherian mammals. Consult: Cope, "The Tertiary ilarsupialia," in American Naturalist (Pliiladeli)hia, 1884) ; Marsh, "American Juras- sic Mammals," in American Journal of Science, vol. xxxiii., ser. 31 (New Haven, 1887) ; Osborn, "On the Structure and Classification of the Meso- zoic Mammalia," in Journal of the Academy of Natural Science, Philadelphia, ser. 2, vol. ix. (1888); id., "Supplementary Note on the Above," in Proceedings uf the Academy of Nat- ural Science (Philadelphia, 1888). CTENOID (te'noid) FISHES (Gk. ktcvo- €iSi>s, kienoeidcs, comb-like, from kte/s, Icieis, comb + elSos, eidos, form). One of the four orders into which Agassiz classified fishes, the others being cycloid, placoid, and ganoid. The name refers to the scales, which bear teeth or sharp projections on the posterior or free mar- gin. These teeth may be in one or more rows. This classification has been abandoned, since evi- dently unrelated forms may show this character. Such ctenoid scales characterize the more recent fishes, as perch and flounders. CTENOPHORA, te-nof'6-ra (Neo-Lat. nom. pi., from Gk. ktcIs, kieis, comb -^- <f>4peip, phe- rein, to bear, carry). A class of crelenterates, composed of jellyfish, characterized by the ab- sence of nettle-cells and the near approach to bilateral symmetry. The ctenophores are dis- tinguished by the presence of eight external rows of minute plates, made from fused cilia, begin- ning near the aboral pole and running doAMi to- ward the mouth, which have given the name 'comb-jellies' to this group. The body is almost transparent, and is oval, more or less elongated, rarely band-shaped, as in the girdle-of-Venus (q.v. ). The gastrovaseular system of canals is rather complicated and difl'ers from that of other coelenterates by opening at the aboral pole, with two small outlets; between these is a remark- able and complicated sense-organ, which serves as an eye and a positional organ. The body is often prolonged on each side of the mouth as a flap or fold, by the movements of which the ani- mals swim. The eight rows of so-called swim- ming plates are probably quite as much respira- tory as locomotive. On each side of the body is a long tentacle, with branches on one side, capa- ble of being greatly extended or completely re- tracted into a protecting sheath. In a few forms these tentacles are wanting. More than 100 species of ctenophoies are known, all marine. The largest ones are only three or four inches in length, but the girdle-of-Venus is sometimes five feet broad. They are usually colorless, but are sometimes yellowish or brow^lish, and the move- ment of the swimming plates sometimes makes them strikingly iridescent. Many species are notably phosphorescent. Consult: L. Agassiz, Contributions to the Natural History of the TJnited States, vol. iii., pt. 2 (Boston, 1860) ; A. Agassiz, papers in Memoirs of the Museum of Comparative Zoology (Cambridge, Mass., 1875 et seq. ) . See Ccelenterata. CTESIAS, te'si-as (Lat., from Gk. Kriyo-fas. Ktesias). A Greek physician and historian of the fifth century n.c. He was a native of Cnidus. In B.C. 415 he was captured by the Persians, and on account of his knowledge of medicine wat kept at the Persian Court some seventeen j'ears. In 398 he returned to his home, where he wrote a comprehensive work on Persia ( Ylepa-iKii. Per- sika) in twenty-three books, based on the knowl- edge he had gained by his residence and re- searches at the Persian capital. Of this only fragments remain, and an abridgment in Pho- tius ; the latter has likewise preserved an abridgment of another work by Ctesias on India ; we also hear of a geographical treatise. The fragments are edited by C. Miillcr in an ap- pendix to Dindorf, Herodotus (Paris, 1844). Consult: Blum, Herodotus und Ctesias (Heidel- berg, 1836) ; Wachsmuth, Einleitung in das Stiidium der alien Oeschichte (Leipzig, 1895). CTESIBITJS, tft-sib'i-us (Lat., from Gk. Ktj). (t/^ios, Ktcsibios) . A CJreek who was famous for his inventions in mechanics. He lived about B.C. 250. He was born at Alexandria. We owe to him and his pupil. Hero of Alexandria, the force- pump, the water organ, and also the discovery of the elastic force of air, and its application as a motive power. His work on hydraulic machines is lost. CTESIPHON, tes'I-fon (Lat., from Gk. KTTiaiipwv, Ktesipho^') , now Tak-i-1veska. A city on the eastern bank of the Tigris, the common winter residence of the Parthian kings, and finally the capital of the Parthian kingdom. It fell into the hands of the Arabs in a.d. 637, and was later abandoned, its ruins being used to furnish ma- terial for the neighboring Bagdad. Its site is to- day marked by scanty remains, including, how- ever, the facade and arched hall of the Parthian palace. On the opposite bank are the ruins of Sele^icia, and the two cities are together called by the Arabs El-Modein. CTESIPHON. An Athenian orator of the fourth century B.C. He proposed the presenta- tion of a golden cro
to Demosthenes for his
sacrifices in his country's cause; for this he was prosecuted by ^ICschines, but was defended successfully bv Demosthenes in his oration On the Croirn (n!o. 330). CTJAtTTLA DE MORELOS. kwa-oot'la da mo-rji'los, or CUAUTLA MORELOS. A city in tne state of Jlorelos, Jlexico, situated on the river Cuautla ( Map : Jlexico. K 8 ) . It. is the centre of a fertile sugar-growing district, and has .several sugar-mills. Cuautla de Morelog was at one time the residence of the Governor of the State, and is famous for its heroic resistance under Jo.se Maria Morelos y Pavon in 1812 against the attacks of a superior army of Royal- ists. Population, about 14,000. CITBA, ku'ba, 8p. pron. koo'Ba (West Indian Cuhanacan) . An island republic of the West Indies, the largest of the Greater Antilles, situ- ated mainly between latitudes 20° and ?3 N., and longitudes 74° and 85° W., and lying south of the Florida peninsula, fnpiii which it is separated by Florida Straits, about 125 miles wide, and east of the Yucatan peninsula, from which it is sepa- lated by the Yucatan Channel, of nearly an equal width (Map: West Indies, G 3. and special map). The island of Cuba lies nearly east and west; it is long and narrow, having its greatest breadth of about 100 miles at the southeast, and a width of less than thirty miles in its narrowest part, near Havana. The "total length of Cuba is about 780
