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OVA
Sibg o'Jler: this has its fhells round, with tubular fpines. 4- The leaf oyfter. 5, The tortuous oijier, called by many the leg oijier, 6. The thigh oijier,
III. Some oijier s are of a globofe form, and carry fpines on their fhells.
Of thefe we have the following fpecies : 1. The round-fpined oijier. 2. The oijier with flat fpines. 3. The fire-coloured oifter, with large ears. 4. The white-pointed rock oifter'. this is ufually found adhering to ftones. 5. The bridge oijier : this alfo is ufually found affixed to ftones or pebbles, in fuch a manner as to reprefent a bridge ; the feveral fmall ftones its ihell fpreads over making the piers. 6. The furr and rofe- coloured oifter, with flat white fpines. 7. The coral oijier. 8. The medal oifter, fo called from the place near Bourdeaux, where it is found. 9. The oifter with red and blue fpines. 10. The clufter oifter, with variegated fhells.
IV. Some oijlers are of a globofe figure, and jagged with high raifed laminae.
Of thefe we have the following fpecies : 1 . The great foliated oijier of Rumphius, called by fome the Placenta follacea. 2. The filiated orange oifter, from the Baltic. 3. The fquam- mofe or fcaly oi/ia\ca]\ed Scandebec by Rondeletius. 4. The fquammofc oifter, with tubular fpines. 5. The yellow fquam- mofe foliaceous oifter : this fpecies is often found adhering to the feveral kinds of coral, and is not unfrequently itfelf cover- ed with balani or center fhells.
V. Some oijlers are oblong and umbonated.
Of thefe we have the following fpecies: 1. The fmooth ipondylus or afs-foot oijier. 2. The rugofe but not fpinous oijier. 3 The white-plated oijier, with a digitated edge co- vered with rofe-coloured fpines. 3. The yellow-plated oijier, variegated with red and white. 5. The gaidaron oifter of Rondeletius. See Oyster.
OSTRICH, ftrutbh, in zoology. See Struthio.
OS TRUCIUM, a name given by the Latin writers of late ages to the plant called fmyrnium and olulatrum. Macer calls this plant caulis fylvefiris, and lias given to it the virtues at- tributed by the antients to the ftruthion, fuppofing thefe to be the two names of the fame plant ; but this is evinced to be an error by the writings of all theantient Greeks. Theophraftus in particular fays, that the ftruthion is a prickle or thorny plant. This alone is fufficient to prove it can have no rela- tion to the ojlrncium of the later authors, or Alexanders, which is a fmooth unbelhferous plant.
This inaccuracy of the writers who collect their accounts from the ancients, is fometimes of bad confequence; fmce thofe who are unable to have recourfcto the original authors, are mifled fo far as to fuppofe the virtues of one plant may be found in another. See the article Smyrnium.
OSYRIS, in botany, the name given by Linnaeus to a genus of plants, including the cafia of Tournefort, and other au- thors. The characters are thefe : it produces both male and female flowers. In the male flowers the perianthium is one leaved and hollow, and is divided into three fegments, which are a!! of the fame fize, and of an acute oval figure. There are no petals, and the ftamina are three fhort filaments. The antherx are fimple. In the female flowers the cup is of thi fame figure as in the male, but is very fmall and ftands upon the germen of the piftill, and remains on it a long time. There are no petals. The germen of the piftill is roundifli, the ftyle is very flat, and the ftigma roundifh. The fruit is a round berry, having one cell, in which is contained a finale bony feed. Linnesi Gen. Plant, p. 472. Tourn. 448.
Osyris is alfo ufed by fome authcrs forthelinaria or toad-flax. Gcr. Emac. Ind. 2.
OTAPULLI, in botany, a name given by fome authors-.to the tree which produces the gamboge, or gutta ga?nla of the fhops Hort. Malab. Vol.1, p. 41.
O I ENCHY LES, a name given by fome authors to a fyringe made for injecting into the ears
OTHOMAN. See the article Ottoman.
OTHONE, oUoi-u & o8<#m, among the antients, a kind of linnen garment worn by women. Pitifc. in voc.
OTHONI, a word ufed by chemical writers for what they other- wife call the mercury of the phikfophers, or pbiljopbic ops.
OTHONNA, the name given by fome authors to a ftone found in JEgypt, and defcribed to be always in fmall pieces, and of the colour of polifhed brafs: probably it is fome fpecies of the pyrites.
Othonna, in botany, a name given by fome authors to the af- rican marygoid. Get: Emac. Ind. 2.
OTIS, in zoology, the name of a large bird, ca T led in En°-!ifh the buftard. The otis is called tarda and otardes by feveral authors. See Tab. of Birds, N 1 * 28.
In the Linuasan fyftem of zoology, the otis makes a diftincT: genus of birdsoftheorderoftheGallinie; thediftinguifhing cha- racters of which are, that the feet have only three toes each, and thole all placed before, and the head is not adorned with a creft or any other ornament. Lhmai Syftem. Nat. p. 47. It is ot the fize of the common turkey, its beak is like that of the common gallinaceous fowls ; its head and neck are grey ; its belly white, and its back variegated with tranfverfe ftreaks
- of red and black ; it has no hinder toe, by which, and by
its fize, it is ea% diftinguifhed from all the reft of the galli-
naceous kind. It feeds on herbs, and eats very "recdHv the leaves of dandelion, and particularly on the feeds of hemlock, which feems a very ftrange food It is frequent in many parts of England, where there are large heaths and plains: they are very bad fliers, and very difficultly raife thetnfelves up from the ground; but they are extremely fhy, and if they fee a man at a very great diftance, they immediately efcape as fart as they can. Their flefh is efteemed. Ray's orintholog)-, p. 129.
O V\T}L§-digitus, the ear-finger, a name given by authors to the finger next the little one.
OTOMO, in zoology, the name of a bird of the lagopus kind, called alfo lolmejlre, and by the Germans, Jieinbun, that is, Jhnehen. It is of the bignefs of a tame pigeon ; its belly and wings are white, with only a very few brownifh feathers; its head, neck, and breaft are variegated with brown feathers, and the upper part of the neck with black and white ; its beak is very fhort and black, and it has fine red granulated mem- branes over its eyes; its tail is principally black, hut is varie- gated with brown and white ; and its legs and feet are fea- thered to the ends of the toes. Gefner de Avibus. Mr. Ray is of opinion, that this is the fame fpecies of bird, with the common white lagopus, it being no way different but in colour, and thofe birds being faid to change colour in the fummer months. It is caught on the mountains of Germany, and is a very delicate bird f>r the table.
OTTER, in zoology. See the article Lutra.
OTTERPIKE, in zoology, the name of a large fpecies of the draco-marinus, or fea- dragon, called in Englifh the weaver: it is not greatly larger than the weaver, but is of a great variety of beautiful colours; and inftead of the yellow fide-lines which that fifh has, this has rows of large black fpots JVil iugbby's Hift. Pifc. p. 2 g8.
OTTOMAN, or Othoman, an appellation given to the em- pire of the Turks, or rather to their emperors, from Otbtman- nus, or Ofmanhw, the firft prince of the prefent family. See Hcffm. Lex. in voc.
OTTUPLA, in the Italian mufic, fignifies oRuple, or the mea- fure of four times; it is marked with a femi -circle, C; and
fometimes thus : ^Jt~ when it is to be played very quick. In this time, eight quavers are contained in a bar. But it often happens, that fuddenly, inftead of two quavers for every time of the bar, three are required; this is called dodecupla. 'Tis enough to place a 3 over three quavers, or notes of equal va- lue, to fhew that the meafure muft be changed; and when this three is omitted, it fufficientiy demonftrates the meafure to be ottupla again: this makes what is called by the Italians (ittupla } dodecupla, thus :
ottupla.
dodecupla.
Corelli, in the laft movement of his tenth fonata, opera terza, very often ufes an 8 after the dodecupla, to fhew, that the triple there is changed to common time.
OTUS, in zoology, the name of the common b-jrn-ozvl of the fmaller kind, in many refpects different from the' great born- owl or eagle-ozvl. It is a moderately large bird ; its beak is black, and its face furrounded with a double circle of feathers, the outer of which is variegated with fine black, white and brown lines, and the place where both circles join is all the way black ; its belly and the feathers on its legs are brown ; its throat and breaft are covered with feathers black in the middle, with white and brown edges ; its long wing feathers are fpotted with black ; its horns, or feathers that rife up from its ears, are black in the middle and variegated with brown and white at their edges ; and its tail is grey above and yellow underneath, and is variegated with feveral tranfverfe black ftreaks ; its feet are hairy down to the toes. It is common in Italy, and is fometimes caught in fome parts of England, and generally fixes- its abode in mountainous places. Ray's Orni- thol. p. 64.
OVA {Cycl^ — The ingenious Dr. Kerkring was the firft who advanced the generation of all animals to be from ova, and that even man himfelf was produced out of an egg. The fyftem occafioned great raillery at the time, and the author found himfelf under a neceffity of publishing all his obfervations by way of juftification. The eggs which he found in the tef- tlcles of all females countenanced his opinion, and he <*ave figures of the parts in their natural fituation, and of the egc-s which he found in women from the age of eighteen to more than forty, in his different difledtions. Among the other crea- tures he examined, he found many fmall eggs in the tefticles of cows, and other creatures of the viviparous kind, He gives an account of one egg which he had an opportunity of opening about four days after it had fallen into the matrix of a woman, and in this he could perceive the marks of the little embryo, the head of which was diftin&ly to be fcen from the body. Another egg, which he had an opportunity of opening at about a fortnight after conception, afforded him a fight ot a little fecundine. The membrane chorion divided in four places, and the amnion d.vided in the fame manner the navel firing, by which the child was faftened to the fe- cundine;
