orthognathous 
shortness of the jaws which constitutes orthog- 
nathism. The facial angle of an orthognathous skull is 
large (by whichever method it is measured), the term be- 
ing more or less definitely employed as the opposite of 
prognathous or prosognathous, where the angle is small, 
or as the mean between prognathous and hyperorthog- 
nathic or opifthognathous, where the angle is excessively 
large. The facial angles that have been chiefly used in the 
definition of these terms arc known as Camper's, Geof- 
froy Saint-Hilaire and Cuvier's, Jacquart's, and Cloquet's 
(which see, under craniometry). A more recent facial angle 
is that included between the nasio-alveolar line and a line 
drawn through the supra-auricular point and the inferior 
margin of the orbit ; when this is between 83' and 90, the 
skull is said to be orthognathous. The same character is 
also defined by means of the gnathic or alveolar index, 
those skulls with a gnathic index below 98 being orthog- 
nathous ; between 98 and 103, mesognathous ; and above 
103, prognathous. 
orthognathy (6r-thog'na-thi), . [As orthog- 
nath-ouH 4 -i/.] Same as orthognathism. 
orthogon (6r'tho-gon), n. [< L. orthogonius, 
< Gr. i>p8oy&vu>, right-angled, < bp66f, right, 4- 
ywvia, an angle.] A rectangular figure ; a figure 
having all its angles right angles. 
orthogonal (6r-thog'o-nal), a. [< orthogon 4 
-al.] 1. Pertaining to or depending upon the 
use of right angles. 2. Right-angled. Orthog- 
onal axes. Seectmsi. Orthogonal projection. See 
projection. Orthogonal substitution or transforma- 
tion, one which transforms from one set of three mutual- 
ly perpendicular coordinates to another. Orthogonal 
trajectory, a curve cutting all the surfaces of plane 
curves of a family of such loci at right angles. 
Orthogonally (6r-thog'o-nal-i), adv. Perpen- 
dicularly; at right angles; with right angles. 
orthograph (or'tho-graf), n. [< Gr. 6p0o?, 
straight, + ypdfyuv, write (see orthography).] 
An orthographic projection; specifically, an 
orthographic drawing exhibiting a structure in 
external or internal elevation. The internal 
orthograph is usually called a vertical section, 
and sometimes a sciagraph. 
orthographer (6r-thog'ra-fer), re. [< orthogra- 
ph-y 4- -er 1 .] One who is skilled in or writes 
on orthography ; one who spells words correct- 
ly, according to approved usage. 
orthographic (6r-tho-graf 'ik), a. [= F. ortho- 
graphiquc = Sp. ortografico = Pg. orthographico 
= It. ortografico, < NL. orthographicus, < L. 
orthographia, < Gr. bp0oypa<t>ia, correct writing 
(also, in L., the elevation of a building) : see or- 
thography.] 1. Pertaining to orthography ; be- 
longing to the writing of words with the proper 
letters ; relating to the spelling of words : as, 
an orthographic error; orthographic reform. 
2. In geom., pertaining to right lines or angles. 
Orthographic projection. See projection. 
orthographical (6r-tho-graf 'i-kal), a. [< ortho- 
graphic 4- -at.] Same as orthographic. 
orthographically (6r-tho-graf 'i-kal-i), adv. In 
an orthographic manner, (a) According to the rules 
of proper spelling or the customary forms of words, (b) 
In the manner of orthographic projection. 
orthographist (6r-thog'ra-fist), n. [< orthogra- 
ph-y 4 -ist.] One who is versed in orthogra- 
phy; an orthographer. 
orthographize (6r-thog'ra-fiz), v. i. ; pret. and 
pp. orthographized, ppr. ofthographizing. [< or- 
thograph-y 4 -ize.] To write or spell correctly. 
Coles, 1717. [Rare.] 
orthography (6r-thog'ra-fi), . [Early mod. E. 
ortograpnie, artografie ; <. F. orthographic = Sp. 
ortografia = Pg. orthographia = It. ortografia 
= G. orthographic = Sw. Dan. ortografi, orthog- 
raphy, spelling, < L. orthographia, ML. also 
orthografia, < Gr. bp6oypa<j>ia, correct writing 
(also, in L., the elevation or front view of a 
building), < *bp6oypa<po(; (> LL. orthographus), 
writing correctly, an orthographer, < bpffof, 
straight, right, correct, 4- ypcupuv, write.] 1. 
The art or practice of writing words with the 
proper letters, according to accepted usage; 
the way in which words are customarily writ- 
ten ; spelling : as, the orthography of a word. 
Such rackers of orthography, as to speak dout, flue, when 
the should say doubt ; det, whert he should pronounce 
debt d, e, b, t, not d, e, t ; he clepeth a calf, cauf ; half, 
hauf ; neighbour vocatur nebour ; neigh abbreviated ne. 
This is abhominable, which he would call abbominable : 
it instnuateth me of insanie. Shak., L. L. L., v. 1. 22. 
(In the following passage it is used erroneously, in bur- 
lesque : 
He was wont to speak plain and to the purpose, like an 
honest man and a soldier ; and now is he turned orthogra- 
phy [that is, orthographer], his words are a very fantasti- 
cal banquet, just so many strange dishes. 
Shak., Much Ado, ii. 3. 20.) 
2. The branch of language-study which treats 
of the nature and properties of letters, and of 
the art of writing words correctly. 
Orthographic that is to say, the forme and precise rule 
of writing set down by grammarians. 
Holland, tr. of Suetonius, p. 77. 
4102 
3. In musical notation, the art or practice of 
representing tones and effects by the proper 
characters, according to accepted usage. 4f. 
In draftsmanship, a geometrical representation 
of an elevation or section of a building ; a sec- 
tional view of a fortress or the like. 
Orthography, or the erect elevation of the same in face 
or front, describ'd in measure upon the former idea, where 
all the horizontal lines are parallels. 
Evelyn, Architects and Architecture. 
Orthologyt (6r-thol'o-ji), . [< Gr. bpOotayia, 
exactness of language, < bpSoXoyciv, speak cor- 
rectly, < 6p6Vif, right, correct, + Aiyeiv, speak.] 
The right description of things. 
The natural and . . . homogeneal parts of grammar be 
two : orthology and orthography ; . . . the first of them, 
orthology, . . . the right imposition of names ; . . . the 
second of them, orthography, . . . the rare invention of 
letters. Fotherty, Atheomastix (1622), p. 34U. 
orthometric (6r-tho-met'rik), a. [< Gr. bptivr, 
right, + fierpov, a measure: see metric 1 .] In 
crystal., pertaining to the three systems in which 
the axes are at right angles with each other. 
See crystallography. 
orthometry (6r-thom'et-ri), n. [< Gr. bpOAf, 
right, correct, + -fitrpla, < iikrpov, measure: see 
meter' 1 '.'} The art or practice of constructing 
verse correctly; the laws of correct versifica- 
tion. 
orthomorphic (6r-tho-m6r'fik), a. [< Gr. bp66f, 
correct, + /lopifiq, form.] In math., preserving 
the true or original shape of the infinitesimal 
parts, though it may be expanding or contract- 
ing them unequally. 
Orthoneura (6r-tho-nu'ra), n. pi. [NL., < Gr. 
bpf)6f, straight, + vevpov, nerve.] In Gegen- 
baur's system of classification, a series of proso- 
branchiate gastropods, including very numer- 
ous genera and families, contrasted under this 
name with Chiastoncura. 
orthoneural (6r-tho-nu'ral), a. [< Orthoneura 
+ -al.] Pertaining to the Orthoneura, or hav- 
ing their characters. 
orthoneurous (6r-tho-nu'rus), a. [< Ortho- 
neura + -ous.] Same as orthoneural. 
Orthonycidse (6r-tho-nis'i-de), n. pi. [NL., 
prop. * Orthonychidai, < Orthonyx (-onych-) + 
-ida!.] A family of oscine passerine birds, typi- 
fied by the genus Orthonyx, having the carotid 
artery sinistral and superficial. O. Salvin. 
Orthonycinae (6r"tho-ni-si'ne), . pi. [NL., 
prop. *Orthonychinw, < Orthonyx (-onych-) + 
-in<K.~\ The Orthonycida; regarded as a sub- 
family of Menurida; or of Certhiidce. G. B. Gray. 
orthonycine (6r'tho-nis-in), a. [< Orthonyx + 
-ine 2 .] Having the characters of the genus Or- 
thonyx; pertaining to the Orthonycinw or Ortho- 
nycida;. 
Orthonyx (or'tho-niks), n. [NL., < Gr. bp66r, 
straight, right, -f- ovtf (omx-), claw: see onyx.] 
A remarkable Australian genus of passerine 
birds ; the spinetails. It long remained of uncer- 
tain position, having been referred to the Certhiidce or 
creepers, to the Menuridce or lyre-birds, to the TimeliidcK 
prolonged beyon 
webs. 0. spaldingi is another species. 
Orthopaedia (6r"tho-pe-dl'a), . [NL., < Gr. 
bpOof, straight, 4- TTCU (ndiS-), a child.] The 
act of curing or remedying deformities in the 
bodies of children, or generally in the human 
body at any age. 
orthopaedic, orthopedic (6r-tho-pe'dik or 
-ped'ik), a. [< orthopwdia 4 -ic.] Relating to 
orthopsedia, or the art of curing deformities. 
Orthopaedic surgery, surgery directed to the remedying 
of distortions. 
orthopaedical, orthopedical (6r-tho-pe'di-kal 
or -ped'i-kal), a. [< orthopaedic + -al.] Same 
as orthopeetlie. 
orthopaedics, orthopedics (6r-tho-pe'diks), n. 
[PI. of orthopaidic: see -ics.] Orthopedic sur- 
gery; orthopwdia. 
orthopaedist, orthopedist (6r'tho-pe-dist), n. 
[< orthopaidia + -ist.] One who practises or- 
thopeedia; one who is skilled in curing natural 
deformities in the human body. 
orthopaedy, orthopedy (6r'tho-pe-di), . Same 
as orthopaedia. 
orthophonia (6r-tho-fo'ni-a), re. [NL. : see or- 
thophony.] Normal voice. 
orthophony (6r'tho-fo-ni), . [< Gr. bp66s, 
straight, + 0wi^, voice, sound.] The art of 
correct speaking; systematic cultivation of the 
voice. 
orthpphoria (or-tho-fo'ri-a), . [< Gr. op%, 
straight, + -<t>6pof, <' tpepttv" carry, = E. bear 1 .] 
The tendency to parallelism of the visual axes. 
orthopterology 
orthophyre (6r'th(i-fir), n. [< ortho(clase) + 
(/>'>r)/ilii/r(i/).] Orthoelasc porphyry. 
orthopinacoid (6r-tho-pin'a-koid), n. [< Gr. 
bp66f, straight, + jrivo (mvaK-), a board, plank, + 
tiJof, form. Cf. pinacoid.] In crystal., a plane 
of a monoclinic crystal which is parallel to the 
vertical axis and the lateral axis perpendicular 
to it. See pinacoid. 
orthopinacqidal (6r-tho-pin-a-koi'dal), a. [< 
orthoptnaeoid + -al.] Pertaining to or in the 
direction of the orthopinacoid. 
Prismatic, ortho- and vlino-pinacoidal cleavages are pres- 
ent. Quart. Jour. Oeol. Sue., XLV. ii. 2!. 
orthopnic (6r-thop'nik), . [Irreg. < orthop- 
ncea T -ic.] A person affected with orthop- 
noaa; one who can breathe in an upright posi- 
tion only. 
Pro ratione victus, as they prescribe for the asthma, 
which is a disease in the body, to avoid perturbations of 
the mind : so let this orthopnic, for the help of his mind, 
avoid needless perturbations of the body. 
Rev. T. Adams, Works, I. 605. 
orthopncea (6r-thop-ne'a), n. [L., < Gr. bpfio- 
nvoia, a kind of asthma which admits of breath- 
ing only in an upright posture, < bp66nvoof, 
breathing only when upright, < option, straight, 
erect, + -KVUV, breathe.] Dyspnoea, as in some 
cases of heart-disease in which respiration can 
be effected only in an erect sitting or standing 
posture. 
orthoprazis (or-tho-prak'sis), n. [< Gr. bpSla;, 
straight, + vpa^if, a doing: see praxis.] The 
treatment of physical deformities by mechani- 
cal agency. 
orthppraxy (6r'tho-prak-si), n. [< Gr. bp66f, 
straight, + n-po^if, a doing: see prajcis.] 1. 
Correct practice, action, or procedure. 
What then constitutes grammatical orthopraxy? 
F. Hail, Mod. Eng., p. 86. 
2. Same as orthopraxis. 
orthoprism (or'tho-prizm), n. [< Gr. 6p0of, 
straight, + wpia/ui, prism.] In crystal., a prism 
of a monoclinic crystal lying between the unit 
prism and the orthopinacoid. 
orthopter (6r-thop'ter), . An orthopterous in- 
sect ; an orthopteran or orthopteron ; any mem- 
ber of the Orthoptera. 
Orthoptera (6r-thop'te-ra), n.pl. [NL. (La- 
treille, 1806) (F. Orthopteres, Olivier, 1789), 
neut. pi. of orthoptents, straight-winged: see 
orthopterous.] An order of the class Insecta 
proposed by Olivier in 1789 for certain straight- 
winged insects which Linneeus had placed in 
Hemiptera, and to which De Geer in 1773 had 
restricted the order Hemiptera. placing the true 
bugs in a new order Dermaptera. The order as 
now understood contains insects in which metamorphosis 
is incomplete and wings are almost always present, of 
which the hinder pair are dilated, folded from the base, 
and of membranous texture, while the fore pair are more 
or less coriaceous, usually narrow and straight (but variable 
in this respect), and thickly veined. These insects are 
active and capable of feeding in all stages from birth to 
death. Seven families or, as some consider, tribes or 
superfamilies are now recognized. These are the Slatti- 
dce,OT cockroaches; M anlidai, or praying-insects; Phasmi- 
doe, or walking-sticks; Oryllida?, or crickets; Locustidoe, or 
long-horned grasshoppers or katydids ; and Acrididce, or 
short-horned grasshoppers or true locusts, including the 
migratory species. (See locust for an explanation of the 
fact that the Locitstidce are not locusts.) The Orthoptera 
are in the main herbivorous, but the Mantidai are carnivo- 
rous, and some of the Blattidce are omnivorous. They are 
found all over the world, but most numerously in the 
tropics, where among them are the largest known repre- 
sentatives of the whole insect class. All the known spe- 
cies are terrestrial or arboreal, no aquatic forms having 
been discovered ; and according to their habitual mode of 
progression the families have been grouped by Westwood 
as Cursoria, Kaptoria, Amlmlatoria, and Saltatoria. The 
Orthoptera are among the earliest forms of insect life to 
appear in geologic time, and the Blattidoz in particular are 
very numerous in some geological formations. The main 
characters used in classifying the Orthoptera are derived 
from the modifications of the genitals, mouth-parts, and 
antenna!. See cuts under Blattidte, Oryllidae, Insecta, katy- 
did, locust, and Mantis. 
orthopteral (6r-thop'te-ral), a. Same as or- 
thoptcrous. 
orthopteran (6r-thop'te-ran), a. and n. I. a. 
Same as orthopterous. 
H. n. An insect of the order Orthoptera. 
orthopterist (6r-thop'te-rist), re. [< NL. Or- 
thoptera + -ist.] One who studies or collects 
Orthoptera. 
orthopterological (6r-thop"te-ro-loj 'i-kal), a. 
[< orthopterolog-y + -ic-al.] Pertaining'to or- 
thopterology, or the study of Orthoptera. 
orthopterolbgist (6r-thop-te-rol'o-jist), .. [< 
orthoptcrolog-y + -ist.] One who makes a spe- 
cialty of the study of Orthoptei-a; an orthop- 
terist. 
orthopterology (6r-thop-te-rol'o-ji), n. [< NL. 
Orthoptera + Gr. -Aoy/a, < 1.iyuv, speak : see 
