OCTAHEDRON ODD FELLOW angles are respectively equal to each other. OCTAHEDBON, in geometry, a solid contained by eight equal and equilateral angles. It is one of the five regular bodies. OCTANS ("the Octant"), the constel- lation surrounding and including the South Pole of the heavens, and one of the 14 added to the heavens by Lacaille in connection with his work at the Cape of Good Hope. Its brightest star is of the 3.8 magnitude. The star Sigma Octantis, of the 5.8 magnitude, lies at present within about %° of the South Pole, nearer than any equally bright star to the North Pole, and it is much used in the Southern Hemisphere for the deter- mination of the azimuth of transit in- struments. The constellation is sur- OCTAVO, the size of one leaf of a sheet of paper, which has been folded so as to make eight leaves; hence, applied to a book printed with eight leaves to the sheet. It is generally written 8vo, and varies in size according to the sizes of paper employed; as, foolscap octavo (or 8vo), imperial octavo (or 8vo), etc, OCTOBER, the 8th month of the so- called year of Romulus, which became the 10th when Numa changed the com- mencement of the year to Jan, 1, though it retained its original name. Many Ro- man and Greek festivals were celebrated in this month, the most remarkable of which was the sacrifice at Rome of the October horse to the god Mars. OCTOPUS, in zoology, the typical genus of the family Octopodidx. The body is oval, warty, or cirrose, finless; OCTOPUS rounded by Hydrus, Mensai_Cham8eleon, Musca, Triangulum australis, Apus, Pavo, Indus, and Tucana. See Transit In- strument. OCTAVIA, sister of Augustus, re- nowned for her beauty and purity of character, and practical wisdom. She was first married to Marcellus, a noble Roman of consular dignity, and soon af- ter his death (40 B. c.) , to Mark Antony. This marriage, it was hoped, would strengthen the new alliance between Oc- tavius, her brother, and Antony, her hus- band. But Antony had seen Cleopatra, and he treated his wife with a contempt and cruelty which Octavius could not for- give, and which became the occasion of renewed war.^ When Antony set out for the East again, Octavia was not allowed to accompany him. She died in 11 B.C. arms long, unequal, suckers in two rows, mantle supported in front by the bran- chial septum. In the male the third right arm is hectocotylized. Found on the coasts of the temperate and tropical zones. Forty-six species are known, varying in lengfth from one inch to more than two feet. The females oviposit on seaweeds or in empty shells. They are sold in the markets of Smyrna and Naples, and India. OCTROI, an old French term signi- fying a grant, privilege, or monopoly from government to a person or to a company. Also a tax levied at the gates of French cities, towns, etc. ODD FELLOW, a member of the In- dependent Order of Odd Fellows, a secret fraternal society instituted in Eng-
