OPHIUCHUS 



244 



OEANG-TTTAN 



Ophiuchus, (of-i-u'kns). [Gk. ophis, serpent; 

 echein, to hold.] The Serpent Bearer: a con- 

 stellation, of which Ras Alagne is the chief 

 star. 



Ophiura, (of-i-u'ra). [Gk. ophis, snake; oura, 

 tail.]= Brittle-stars: animals, belonging to 

 Echmodermata, the type of Ophiuridse. 



Ophiuridse, (of-i-u'ride). [Gk. ophis, serpent; 

 oura, tail; eidos, form.] Brittle-stars, Sand- 

 stars, &c. : a division of Ophiuroidea. 



Ophiuroideae, (of - i-u -roi'de - a). [Gk. ophis, 

 serpent; eidos, form.] Brittle-stars, Sand- 

 stars : a division of Echinodermata, hav- 

 ing a flat body, with long and slender 



Ophry's, (6'fris). [Gk. ophrys, eyebrow.] An 

 herb belonging to Orchidaceee, q.v. 0. api- 

 fera = Bee-orchis. 0. aramfera = Spider- 

 orchis. 0. r/msci/<?ra= Fly-orchis. 



Ophthalmia, (of-thal'mi-a). [Gk. ophthalmos, 

 eye.] A diseased condition of the eye. 



Ophthalmic, (of-thal'mik). [Gk. opthalmos, 

 eye.] 0. artery: termination of internal 

 carotid artery, serving the eye. 0. nerve: 

 a division of the trigeminal nerve itself 

 subdivided into the nasal and lachrymal 

 nerves. 



Ophthalmoscope, (of-thal'mo-skop). [Gk. 

 ophthalmos, eye; skopeo, I view.] An instru- 

 ment for the examination of the structure 

 and condition of the eye, by concentrating 

 on it the light of a lamp, by means of a 

 lens. 



Opiammon, ( o-pi-am'mon ). ^ [Opianic and 

 Ammo ilium, q.v.] CooHjgNOs : an amide- 

 like compound obtained from opianate of 

 ammonium. 



Opianic acid, (o-pi-an'ik ). [Opium.]= 

 Ci H 10 O 5 : found in Narcotine. 



Opianine, (6'pi-a-nin). [Opium, q.v.] An 

 organic base from opium. 



Opianyl, (6'pi-a-uil). [Opianic, q.v.] CioHgC^: 

 the radicle of opianic acid. 



Opisthobranchiata, ( 6-pis-tho-brang-ki-il'ta ). 

 [Gk. opisthe, behind; brachion, gill.]=!3ea- 

 slugs: a sub-division of Branchio-Gastero- 

 poda, q.v. 



Opisthocoelia, (o-pis-tho-sg'li-a). [Gk. opisthe, 

 behind; koilos, hollow.] Crocodiles, known 

 only by fossil remains: named from the an- 

 terior vertebrae being concave behind. 



Opisthocomus, (6-pis-thok'o-mus). [Gk. opis- 

 the, behind; kome, hair.] Crested-pheasant; 

 a gallinaceous bird of Brazil. 



Opisthodelphys, ( 6-pis-tho-delf is ). [Gk. 

 opisthe, behind : adelphos, brother. ] A 

 tree-frog with dorsal egg-pouch : found in 

 America. 



Opisthotic, (o-pis-thot'ik). [Gk. opisthe, be- 

 hind; ous, ear.J A bony portion of the audi- 

 tory capsule. 



Opium, ( 6'pi-um ). [The Latin name.] The 

 dried juice of the white poppy: a body 

 of very compound character. 0. poppy = 

 Papaver somniferum. Tincture of 0.= 

 Laudanum. 0. alkaloids='M.oi-phia., codeia, 

 papaverine, &c., q.v. 



Oporobia, (6-po-ro'bi-a). 0. dilatala='Novem- 

 ber moth. 



Oposin, (6'pos-in). An albuminous substance 

 obtained from flesh. 



Opossum, (o-pos'sum). [Opassom, the Indian 

 name. ] = Didelphis, 

 &c. : a marsupial ani- 

 mal, found only in 

 America. Vulpine 

 0.=Phalangista vul- 'ft. 

 pina. 0. shrimps= A 

 Mysis. 



Opposition, (op-po- 

 zish'un). [L. oppono, 

 I place opposite to.] 

 A planet is in opposi- 

 tion when it and the 

 sun are on opposite Opossum, 



sides of the earth in the same straight lino 

 with it. 



Opsaisthenics, ( op-sis- then'iks ). [Gk. ops, 

 eye; aisthesis, feeling. ] = Eye -sensations: 

 sight. 



Opsimose, (op'si-mos). [Gk. opsimos, late.] 

 =Klipsteinite: a mineral. 



Optic, (op'tik). Optikos, the Greek word.] 

 0. axis: the straight line joining the centres 

 of the eye, and of any object immediately in 

 front of it. 0. angle: the angle between the 

 axes of the two eyes. 0. lobes: the portion 

 of the brain from which the optic nerve pro- 

 ceeds. 0. nerves : the second pair of cerebral 

 nerves, which terminate in the retina of the 

 eyes: not properly nerves, but rather pro- 

 cesses of the brain, ending in red and yellow 

 knobs. 0. thalami : masses of nervous mat- 

 ter in the brain. 0. tracts: unite to form 

 the optic nerves. 



Optical=Optic, q.v. 0. couple', v. Couple. 



Optics, (op'tiks). [Gk. optikos, relating to 

 the sight.] The science of the nature 

 and laws of the phenomena of vision, in- 

 cluding the construction of optical instru- 

 ments, such as the telescope, microscope, 

 &c. 



Optometer, (op-torn e-tev). [Optics and Meter, 

 q.v.] An instrument for the measurement 

 of the distance of distinct vision for any 

 given person. 



Opuntia, (6-pun'shi-a. ) [Opuntus, a town in 

 Greece.] Indian figs^Cactus opuntia: plants 

 belonging to Cactaceae. 



Orach, (or'ak) = Atriplex, a plant belonging 

 to Chenopodacese. Halimus 0.=Tree pur- 

 stane. 



Orange, (or'anj). [Naranj, the Arabic name.] 

 =Citrus aurantium. A plant 

 belonging to Aurantiacese, 

 which flowers all the year* 

 round in Brazil. Bergamot 0. 

 =. Citrus bergamia. Manda- 

 rin 0.:=Citrus nobilis. Quito 

 0. = Fruit of Solatium. 0. 

 lily=~Lili\im bulbiferum. 0. 

 red s<ars=Betelgeuse, Pollux, 

 &c. 0. pigments = Ochre, 

 chromium, lead, chalk, and 

 compounds of these. 0. tip Orange. 

 6wer%=Anthocharis cardamines. 



Orangi'te, (or / *n-jIt)=Thorite, q.v. 



Orang-utan, (6-rang'o-tang'). [Malay, outang, 



