Hyoganoidei 
paratus and branehiostegal rays like those of 
the teleosts. It includes the orders Cycloyanoidei and 
Wwrnbuijannidri. represented in the existing fauna only 
by the Xiniuiirand LffUatMia, butin ancienttimes hav- 
ing numerous and diversified representatives. Gill. 
hyoglossal (hi-o-glos'al), a. and H. [< hyo(id) 
+ Gr. y^aaaa, tongue, + -al.] I. a. Pertaining 
to the hyoid bone and the tongue Hyoglossal 
membrane, a fibrous sheet connecting the base of the 
tongue with the hyoid bone. Hyoglossal muscle, the 
hyoglossus. 
II. . Same as hyoglossus. 
hyoglossus (hl-o-glos'us), M. ; pi. hyoglossi (-1). 
[NL., < hyo(id) + Gr. ykuaaa, tongue.] A mus- 
cle of the hyoid bone and the tongue, in man 
the hyoglossus is a thin, flat, somewhat square muscle, 
arising from the whole length of the hyoid Done, on each 
side of its body, and inserted into the side of the tongue 
between the stylogloasus and lingualis. The origin of the 
muscle from different parts of the hyoid bone, namely 
from the body and the lesser and greater cornua, has caused 
the description of the muscle as three, called basioglonmis, 
ceratoglosntu, and chondrogloaua. Also called liasiacerato- 
chundrogl(ussu. 
hyoid (hi'oid), a. and n. [= F. hyoide, < NL. hy- 
oides,< Gr. wetot/c,, shaped like the letter upsilon, 
Y, now commonly printed T, v ; oarovv {metier,, 
the hyoid bone (also called i^Xottdjfa, upsilon- 
shaped, and ><///.M< $/,, lambda-shaped [A] : 
see upsilon, and lambda, lambdoid); < v, the let- 
ter upsilon, + cloof, form.] I. a. Having the 
form of the Greek letter upsilon, T. in biology 
and embryology it is applied to the bony or hard parts 
developed in the second postoral visceral arch of the em- 
bryo, this being called the hyoid or hyoidean arch or ap- 
paratui, as distinguished from preceding mandibular or 
succeeding branchial parts. Hyoid bone. Same as hy- 
oid, n. 
II. 11. The tongue-bone or os linguae; the 
hyoidean bone or collection of bones : so called 
from its shape in man. In man it is embedded in 
the muscles of the root of the tongue, lying nearly hori- 
zontal with its convexity forward, usually about on a level 
with the lower border of the under Jaw, considerably 
above the Adam's apple ; but it is displaced in every act 
of swallowing. This horseshoe-shaped arch forms the 
bony basis of the tongue. (See cut under mouth.) No 
fewer than 10 muscles arise from or are inserted into it; 
and it is besides suspended from the skull by the stylo- 
hyoid ligament, and connected with the larynx by the 
thyrohyoid membrane and ligament, and with the epi- 
glottis by the hyo-epiglottic ligament. Its comparatively 
small size and simple structure in man are unusual : in 
most animals the bone is either relatively larger, or con- 
sists of a number of separate bones, indications of which 
are found in the human species In the several ossinc 
2940 
Diagrams of the mandibular I. shaded) and hyoidean (II, unshad- 
ed) arches of a lizard i A), a mammal (B). and an osseous fish (C). 
I. Mck, Meckel's cartilage ; Art, atticulare ; Qu, quadratum ; Mpt, 
metapterygoid ; M, malleus; fe, processus gracilis ; Pt, pterygpid 
bone. II. Hy. hyoidean cornu ; StH. styloliy.it ; S, stapedius ; $//, 
stapes: Sstf, supra-stapedial ; Hm, hyomandibular bone ; PC, peri- 
otic capsule. The arrow is in the first visceral cleft. 
centers from which the bone originates. Thus, the body 
of the human hyoid is the basihyal ; the lesser cor- 
nua or horns are the ceratohyals, and the greater cornua 
are the thyrohyals. (See cut under skull.) In a saurop- 
sidan, as a bird, the so-called hyoid bone is the whole 
skeleton of the tongue, consisting of several parts devel- 
oped in a branchial arch, as well as hyoidean parts prop- 
erly so called. These pails are the basihyal, glossohyal, 
and ceratohyal or epihyal of the hyoidean arch proper ; with 
the urohyal or basibranchial, the epibrauchial, and the cer- 
atobranchial, these three belonging to a branchial arch, 
and the last two of them being commonly known as the 
thyrohyal or greater cornu of the hyoid bone. The ele- 
ments of the hyoid bone of an osseous fish are the basi- 
hyal, glossohyal, urohyal, epihyal, ceratohyal, and stylo- 
hyal. 
hyoideal (hi-oi'de-al), a. [< hyoid + -e-al.] 
Same as hyoid. 
This development [of the skull] relates to the protection 
and support of the still more extraordinarily developed hy- 
oideal and laryngeal apparatus [of the howlers]. 
Owen, Anat., II. 531. 
hyoidean (hi-oi'de-an), a. [< hyoid + -e-an.] 
Same as hyoid. 
hyomandibular (hi'd-man-diVu-lar), a. and n. 
[< hyo(id) + mandibular.'] I. a. Pertaining to 
the hyoid bone and to the mandible or lower 
jaw. 
The hyoidean arch becomes segmented into two note- 
worthy portions, the upper of which is known as the hyo- 
mandibular portion. Mimrt, Encyc. Brit., XXII. 114. 
Hyomandibular bone, in fishes, the bone or element of 
the suspensorium of the lower jaw next to or articulating 
with the cranium. Also called epitympanic and temporal. 
H. n. Same as hyomandibular bone. 
hyomental (hi-o-men'tal), a. [< hyo(id) + 
mental 2 .] Pertaining to the hyoid bone and 
the chin. 
hyoplastral (hl-o-plas'tral), a. Of or pertain- 
ing to the hyoplastron. 
hyoplastron (hi-o-plas'tron), H. [< hyo(id) + 
plastron.] The second lateral piece of the 
plastron of a turtle : a name given by Huxley to 
what others call the hyostenium. See second 
cut under Chelonia. 
Hyopotamida (hi'o-po-tam'i-de), . pi. [NL., 
< Hyopotuiitus + -idd'.] A family of omnivo- 
rous ungulate mammals, represented by the 
genus Hyopotamus and related to the SuidiE, or 
swine. Kowalewsky. 
Hyopotaminae (lu-o-pot-a-nri'ne), n.pl. [NL., 
< Hyopotamus 4- -iiue.] The Hyopotamidte re- 
garded as a subfamily of Antltraeotkeriulte, hav- 
ing the four upper premolars resembling the 
true molars, and with tubercles in transverse 
series separated by transverse valleys, and the 
preceding three molars successively more and 
more differentiated. Besides Hyopotamus, the 
subfamily contains the genus Bothriodon (Ay- 
mard) or Ancodus (Pomel). T. Gill, 1872. 
Hyopotamus (hi-o-pot'a-mus), n. [NL., < Gr. 
t'f, a pig, hog (= L. sus = E. sow 2 ), + 7roro//of, 
river. Cf. hippopotamus.] A genus of fossil 
non-ruminant artiodactyl mammals, supposed 
to have been of aquatic habits and related to 
swine, whence the name, given by Owen in 
1848. The remains occur in the Tertiary strata, Eocene 
and Miocene, of England and the continent of Europe. 
The genus has been referred to the Xiiiilit and to the .1 - 
thracotheriidce, and also made the type of a family Hyopo- 
tamiatE. 
hyoscapular (hi-6-skap'u-lar), a. [< hyo(id) + 
scapular, q. v.] Pertaining to the hyoid bone 
and to the scapula ; omohyoid. 
hyoscine (hi'o-sin), n. [< Hyosc(yamus) + -ne 2 .] 
A uon-crystallizable alkaloid obtainable only 
as a syrup from Hyoscyamus niger. it is known 
In commerce as amorphous hyoscyamine, and its salts are 
used in medicine to some extent. 
Hyoscyamea (hl'o-sl-a'me-e), n. pi. [NL. 
(Reichenbach, 1837), < Hyoscyamus + -e<e.] A 
tribe of plants of the natural order Solanaceas, 
typified by the genus Hyoscyamus, having the 
lobes of the corolla plicate or imbricate, the 
stamens all perfect, and the fruit a capsule. 
hyoscyamine (hi-o-si'a-min), n. [< Hyoscyamus 
T -iwe 2 . Cf. L. hyoscyaminus, < Gr. voaKvdfiivor,, 
of henbane.] A crystalline alkaloid (C^I^g 
NOs) obtained from Hyoscyamus niger, or hen- 
bane. When moist it hasastrong alkaline reaction, and 
a penetrating, narcotic, and stupefying odor like that of 
nicotine. It neutralizes acids, forming salts, some of 
which, particularly the sulphate, are used in medicine. 
The alkaloid is extremely poisonous. Amorphous hy- 
oscyamine. Same as I0MMM. 
Hyoscyamus (hi-o-si'a-mus), n. [L., < Gr. voa- 
Ki'a.uoc, henbane, lit. hog's bean, < Me, gen. of 
t>f, a hog, + Kva/tof, a bean.] A genus of dicoty- 
ledonous gamopetalous plants, of the natural 
order Solanacea', type of the tribe Hyoscyameee. 
They have a tubular-campanulate calyx, an infundibuli- 
forin corolla with an oblique limb and imbricated unequal 
lobes, and a capsule opening by a median transverse cir- 
cumcision, the top falling off like a lid. They are herbs 
with the leaves sinuate-dentate or incised, and yellowish 
flowers in usually 1-sided leafy spikes. About 10 species 
are known, natives of the Mediterranean region and cen- 
tral Asia. H. niger is the henbane or black henbane. See 
cut under henbane. 
Hyoserideae (hi'o-se-rid'e-e), . pi, [NL., < 
Hyoseris (-id-) + -fee.] A' subtribe of compos- 
ite plants, typified by the genus Hyoseris. They 
are herbs, having the pappus more or less chaff y, small, with 
alternate bristles, and the apex of the achenia truncate. 
Hyoseris (hi-os'e-ris), H. [NL., < Gr. if, a 
hog. + oepif, succory.] A small genus of com- 
posite plants, of the tribe Cichoriacea?, the type 
of the subtribe Hyoserideae, having the habit 
and foliage of Taraxacum. The flower-scape is thick- 
ened upward and bears a single yellow flower-head. From 
their near allies they differ in that the achenia are of two 
kinds in each head, the outer corky and cylindrical, the in- 
ner compressed or two-winged. The pappus is biserial, 
and consists of narrow and unequal scales. Four species 
are known from the Mediterranean region, one extending 
into southern Germany. //. minima is the hog-succory. 
Two fossil species very closely related to this genus have 
been described, from the Mioceneof Carniolaand Bohemia, 
under the name Hyonentes. 
hyosternal (hl-o-ster'nal), o. [< hyo(id) + ster- 
nal.] 1. Pertaining to the hyoid bone and the 
breast-bone; steruohyoid. 2. In herpet., of or 
pertaining to the hyoplastron: as, a hyosternal 
scute. 
hyosternum (hl-o-ster'num), n. [< hyo(id) + 
sternum.] The second lateral piece of the so- 
called sternum that is, of the plastron of 
a chelonian ; the hyoplastron of Huxley. See 
second cut under Chelonia. 
hyostylic (hi-o-sti'lik), a. [< hyo(id) + Gr. 
cTiXof, pillar, style.] Having the lower jaw sus- 
Hypapante 
pended from the skull by a special suspenso- 
rium : the opposite of autostylic. 
Most modern researches have also tended to emphasize 
the distinction between fishes with autostylic and those 
with ttyiwtylic skulls. 
A. S. Woodward, Cat. Fossil Fishes, B. M., I. p. vii. (1889). 
hyp, ii. and . See hip*. 
hyp-. See hypo-.' 
hypacusis (hip-a-ku'sis), . [NL., < Gr. i-iro, un- 
der, + aKovaif , hearing, < cucateiv, hear: see acous- 
tic.] Inpathol., diminished power of hearing. 
hypaesthesia(hip-es-the'si-a),H. [NL.,< Gr.i'iro, 
under, + aboqinti perception: see esthetic, etc.] 
In pathol., diminished capacity for sensation; 
a dulled but not obliterated sensitiveness. 
hypaesthesic (hip-es-the'sik), a. [< hi/pa;sthe- 
niii + -ic.] Pertaining to or characterized by 
hyptesthesia. 
hypsethra, . Plural of hyptsthron. 
hypaethral, a. See hypethral. 
When processions of men and maidens bearing urns and 
laurel-branches, crowned with ivy or with myrtle, paced 
along those sandstone roads, chanting peeans and proso- 
dial hymns, toward the glistening porches and hypatthral 
cells. J. A. Symonds, Italy and Greece, p. 191. 
hypaethron (hi-pe'thron), .; pi. hmathru 
(-thrji). [LL. hypcethrum, < Gr. viratffpov, the 
uncovered part of a temple, < vir6, under, + 
a'tOt/p, the sky: see ether*.] In arch., an open 
court or inclosure ; a place or part of a building 
that is hypethral, or roofless. See hypethral. 
The light seems to have been Introduced into what may 
be considered a court, or hypathron, in front of the cell, 
which was lighted through its inner wall. 
J. Fergusson, Hist Arch., L 265. 
hypalgesia (hip-al-je'si-a), n. [NL., < Gr. wro, 
under, + a^.-yr/atf, sense of pain, < atyeiv, be in 
pain, < >;">, pain.] \npntliol.. diminished sus- 
ceptibility to painful impressions; incipient 
analgesia. 
hypalgia (hi-pal'ji-a), . [NL., < Gr. inro, un- 
der, + aAyof, pain.] Same as hypalgesia. 
hypallage (hi-pal'a-je), n. [LL., < Gr. vn-atoarf, 
an interchange, exchange, a figure of speech by 
which the parts of a proposition seem to be in- 
terchanged (metonymy, epidiorthosis, enallage, 
hypallage), < intalMioativ, exchange, < vx6, un- 
der, + atoaoaetv, change, > aUayi/, change, ex- 
change: see allagite. Cf. enallage.] Ingram. 
and rhet., a figure which consists in inversion 
of syntactical relation between two words, each 
assuming the construction which in accordance 
with ordinary usage would have been assigned 
to the Other. Thus, in Virgil (^Eneid, iiL 61), " dare 
classibus austros " (to give the winds to the fleets) Is substi- 
tuted for the usual construction "dare classes austris"(to 
give the fleets to the winds); the dative and accusative 
that is, the indirect and direct objects having been inter- 
changed. Hypallage is a bold departure from the custom- 
ary mode of expression, and is almost entirely confined 
to poetry. Hypallage of the adj ective, the transfer of 
the attribute from that one of two interdependent substan- 
tives with which it would usually agree to the other, espe- 
cially from a substantive in the genitive to that govern- 
ing it. See enallage. 
hypanisognathism (hi-pan-i-sog'na-thizm), n. 
[As hypanixognathous + -isnt.] In zool., that in- 
equality of the teeth of opposite jaws in which 
the lower are narrower than the upper; one of 
two types of anisognathism, the other being 
epanisognathism. Cope. 
hypanisognathous (hl-pan-i-sog'na-thus), a. 
[< Gr. imo, under, + avtaof, unequal, uneven, + 
yvdflof, the jaw.] In zool., having the lower 
teeth narrower than the upper. Cope. 
Hypante (hi-pan'te), n. See Hypapante. 
hypanthia, . Plural of hypanthium. 
hypanthial (hi-pan'thi-al), a. [< hypanthium 
+ -all Of, pertaining to, or resembling a hy- 
panthium: as, a hypanthial receptacle. 
hypanthium (hl-pan'tbi-um), . ; pi. hypanthia 
(-a). [NL., < Gr. into, under, + avSof, a flower.] 
In bot., an enlargement or other development 
of the torus under the calyx. Gray. This term 
has been widely, but incorrectly, applied to the fruit of 
the fig and allied forms, which properly come under ay- 
cotnum or hypanthodium. 
hypanthodium (hi-pan-tho'di-um), . [NL., < 
Gr. wro, under, + NL. anthodium, q. v.] In hot., 
same as syeonium. 
hypantruin (hl-pan'trum), n. ; pi. hypantra 
(-tra). [NL., < Gr. vvavrpof, cavernous, witli 
caverns underneath, < into, under, + avrpov, a 
cavern: see antre.] In anat., the recess in the 
neural arch of a vertebra with which the hypo- 
sphene articulates. See hyposjihene, and com- 
pare zygantritm. 
Hypapante (hip-a-pan'te), n. [LGr. virairavrr/, 
a later form of viravrf/, equiv. to Gr. vjravn/aif, a 
coming to meet, < viravrav, go to meet, < wo, 
under, -f- avrav, come opposite to, < avra, over 
