OPHIDIUM ORACH E. 



and which includes all the serpents and snakes, what- 

 ever be their nature or their modes of life. They are 

 animals of obscure habits, and principally confined to 

 the warmer climates of the world ; and they are the 

 only vertebrated animals which have a distinct ap- 

 paratus for infusing venom into wounds, and thereby 

 occasioning the death of most animals which they 

 bite, and severe pain to all animals. Their general 

 relations will be pointed out in the articles REPTILE 

 and SERPENT. 



OPHIDIUM. A genus of fishes, belonging to 

 the soft-finned ones, which are without ventral fins, 

 and have the body eel-shaped. The body is length- 

 ened and compressed, so that it has been compared 

 to a sword in shape. The scales are very small, and 

 closely embedded in the skin. But though in their 

 general form they very much resemble the eels, yet 

 they differ considerably from them in the structure of 

 their gills, which are open, so that the fishes have 

 more free motion in the water, and cannot live so 

 long when removed from it. The species best known 

 are natives of the Mediterranean. One small species 

 is flesh-coloured, with small black spots on the dorsal 

 and anal fins. Another is larger, of a brown colour, 

 without any spots on the fins, which last one is 

 reckoned very wholesome food. Others are found 

 on the shores of Brazil and in the South Sea, in the 

 last of which there is one of large dimensions, rose: 

 coloured in the ground, and spotted with brown. All 

 these have appendages to the under jaw, of greater 

 or less length in the different species ; but there are 

 others which want these appendages, and also have 

 the dorsal fin nearly obliterated. The largest one is 

 found near the coast of New Zealand, six feet in 

 length : they are much esteemed as food. Their history 

 is very obscure. 



OPHION (Fabricius). A genus of parasitic hy- 

 raenopterous insects, belonging to the family Ichneu- 

 monidce, having the ovipositor of the females scarcely 

 exserted, the abdomen compressed and sickle-shaped, 

 the antennae filiform or setaceous, the second cubital 

 cell of the upper wings is very small or obsolete. The 

 type of the genus is the Ichneumon luteus, Linnaeus. 

 It is of a reddish-yellow colour, and about three- 

 fouiths of an inch long. It often flies into lighted 

 rooms at night. The female deposits her eggs upon 

 the caterpillar of the puss-moth (Ccruravinula), being 

 attached at the extremity of a long and slender foot- 

 stalk. When hatched they reside outside the body 

 of the caterpillar, with the extremity of their bodies 

 placed in the pellicle of the egg, from which they 

 have burst forth. After the caterpillar has spun 

 its cocoon, it is so much exhausted by their attacks, 

 that it soon dies ; the parasites then spin their own 

 cocoons within the cocoon of the dead caterpillar, and 

 soon afterwards make their appearance in the winged 

 state. Mr, Curtis observes respecting this insect, 

 " It has struck me as very remarkable, that one often 

 can obtain only one sex of Ophion from an infested 

 larva, although a considerable number may be 

 hatched; having observed this several times, it can 

 scarcely be accidental. I am therefore inclined to 

 think that one sex appears before the other, and that 

 the eggs of each are deposited separately in different 

 caterpillars." British Entomology, No. 600. 



OPHIOPOGON (Ker). A genus of two curious 

 herbaceous plants from China, belonging to Smilaccce. 

 Generic character : calyx corolla-like, half superior, 

 limb six-cleft, spreading ; stamens above the germen, 



351 



filaments short, anthers erect, long, heart-shaped ; 

 style three-sided ; stigma three-lobed ; berry three- 

 seeded. These plants grow freely in any light rich 

 soil, and are increased by dividing the root. 



OPHIORHIZA (Limueus). An East Indian 

 undershrub, called in that country Mungos, and in 

 China Chyn-lcn, bearing pentandrious flowers, and 

 belonging to Rubiacecc. Its rhizoma or underground 

 stem is called by druggists snakeroot, and is a very 

 strong bitter, highly valued in China. In our stoves 

 the plants are grown in loamy moor-earth, and are 

 increased by cuttings. 



OPHRYS (Linnams). A genus of tuberous- 

 rooted herbs, chiefly natives of European meadows, 

 belonging to the class Gynandria, and natural order 

 Orchidcce. The curious forms of these flowers have 

 gained for them provincial names, by which in com- 

 mon language they are known. One is the bee, 

 another the drone, one is the fly, another the spider, 

 ophrys, &c. The flowers are more curious than 

 showy, but are all admirable, whether in their wild 

 state or in botanical collections. The best artificial 

 soil for them is a mixture of chalk, loam, and moor- 

 earth, but when so cultivated, they require protection 

 as well from long continued rain as from hard frost. 



OPILO (Latreille ; NOTOXUS, Fabricius). A 

 genus of coleopterous insects, belonging to the family 

 Cleridce, having all the palpi terminated by a large 

 hatchet-shaped joint, the antennae gradually thickened 

 to the tips, the intermediate joints being of a Conical 

 form. These are pretty insects, generally of consi- 

 derable rarity, one species only being found in this 

 country (Attelabus mollis, Linnaeus), which is met with 

 under the bark of old trees where the larva has fed 

 upon other wood-boring larvae. 



OPUNTIA (Haworth). A genus of succulent un- 

 dershrubs, commonly called Indian fig from the form 

 of their fruit. The flowers are icosandrous, and the 

 genus belongs to the natural order to which it gives a 

 title, viz. 



OPUNTIACE^E, or CACTE^E. A natural 

 order containing nine genera, and one hundred and 

 fifty-six species. They are all succulent plants, des- 

 titute for the most part of leaves, the place of which 

 is supplied by fleshy stems of the most grotesque 

 shape : some angular, and attaining the height of 

 thirty feet ; others roundish, covered with stiff spines 

 like the hedgehog, and not exceeding the height of a 

 few inches. Their flowers are in many cases large 

 and remarkably specious, varying from pure white to 

 rich scarlet and purple, through all the intermediate 

 gradations of colour. The species are chiefly natives 

 of the hottest and driest parts of the tropics, and are 

 cultivated with little care in pots filled with lime 

 rubbish in a dry stove. Their fruit is fleshy and 

 watery, and generally insipid, but it is eaten in their 

 native countries for the sake of its refreshing mois- 

 ture and coolness. Two species of Opuntia are hardy 

 in Britain. The order consists of two tribes, namely, 

 Opuntiacece and Rhipsalidcce. The first contains Mam- 

 millaria, Cactus, Melocactus, Echinocactus, Cercus, 

 Epipliyllum, Opuntia, and Percskia; the second com- 

 prises the genus Rhipsalis, Lindley. They are all easily 

 increased by suckers, offsets, or cuttings, the moist 

 base of the cutting being first allowed to become dry 

 before placing in the soil. 



OR AC HE is the Atriplex hortensis, a native of 

 Tartary, and belonging to the natural order ,Chcno- 

 podece. It was formerly cultivated in our gardens 



