RATTLESNAKE 440 RAVENNA RATTLESNAKE, the English name for any species of the American genus Crotalus, the tail of which is furnished with a rattle. Garman enumerates 13 species and 13 varieties, falling into two groups: (1) Having the upper side of the head covered with nine dermal shields; (2) having the shields behind the eyes broken up or replaced by small scales. The second group comprises the more formidable kinds, generally de- scribed as C. horridus and C. durissv^. The first name was formerly applied to HEAD OF /RATTLESNAKE A = POIhON GLfr^O RATTLESNAKE the reptile extending from Paraguay and Chile through Brazil, into Mexico, and the latter to the North American rattle- snake. In recent American works this nomenclature is reversed. The poison of the rattlesnake is usually fatal to man, though fortunately they are slug- gish, and never attempt to strike unless they are molested. They are widely dis- tributed on the American continent. RATTLESNAKE ROOT, a name for Poly gala Senega, an American plant used to cure the bite of the rattlesnake. RATTLESNAKE WEED, the Amer- ican plant Eryngium virginiciiTn, used as a cure for the bite of the rattlesnake. RAVANA, in the Hindu religious sys- tem, the name of the Rakshasa who, at the time of Rama, ruled over Lanka or Ceylon, and having carried off Sita, the wife of Rama, to nis residence, was ulti- mately conquered and slain by the latter. He is described as having been a giant with 10 faces, and in consequence of austerities and devotion, as having ob- tained from Siva a promise which be- stowed on him unlimited power, even over the gods. As the jpromise of Siva could not be revoked, Vishnu evaded its efficacy in becoming incarnate as Rama, and hence killed the demon giant. RAVELIN, in fortification a detached work having a parapet and ditch forming a salient angle in front of the curtain. It is erected on the counterscarp, and receives flank defense from the body of the place. Inside the ravelin may be a redoubt and ditch; the gorge is unpro- tected, and the ravelin may be considered a redan on the counterscarp. ^ RAVEN, the genus Ccrrviis, and espe- cially C. eorax, one of the largest of the Passerines. It is about 26 inches long, plumage black, glossed with steel-blue and purple; very widely distributed in the Northern Hemisphere. The raven has played an important part in myth- ology and folk-lore. It is the first bird mentioned by name in the Old Testament (Gen. viii: 7) ; by the ministry of ravens Elijah was fed (I Kings xvii: 6), and they were to be the ministers of venge- ance on unruly children (Prov. xxx: 17). The raven was the bird of Odin, and in classic mythology was of iU- omen, a character often attributed to it by the early English dramatists. Mar- lowe calls it the "sad presageful raven," and Shakespeare repeatedly refers to the belief that its appearance foreboded misfortune. This belief, which is wide- spread, probably arose from the preter- naturally grave manner of the bird, its sable plimiage, and the readiness with which it learns to imitate human speech. RAVENALA, or RAVINALA, a genus of Uy^anem. The U. speciosa is a fine banana-like tree with edible seeds, from Madagascar, where the French call it he traveler's tree, perhaps because water is found in the cup-like sheaths of the ^ leaf-stalks. RAVENNA, an important city and province of central Italy, 43 miles E. S. E. of Bologna, and 4V2 miles from the Adriatic. It is situated in the midst of a well-watered, fertile, and finely wooded plain, and is surrounded by old bastions, and by walls where may still be seen the. iron rings to which the cables of ships were formerly fastened; the sea is now at the distance of about 4 miles from the city. The streets are wide ; the squares are adorned with the statues of the Popes. The cathedral, built in the 4th century, was almost wholly re- built in 1734. Of the other 14 churches and other architectural antiquities sev- eral date from the 5th and 6th centuries. San Francesco possesses the tomb of Dante, erected in the 15th century. The library of Ravenna contains 50,000 vol- umes. It has an archffiological museum, and many educational institutions. Ra- venna has manufactures of silk, and its trade is facilitated by a canal to the
