Pleuracanthidae 
Pleuracanthidae (pl8-ra-kan'thi-de), n. pi. 
[NL., < Plevracanthia + -idx.] A family of 
fishes of the order Xenacanthini, typified by the 
genus Plfiiriii-initliHtt. The body was moderately long ; 
the head roundish; the mouth terminal and well slit; 
the dursal double, the first short, armed with an anterior 
spine, and mostly above the head, the second extending 
from the first to the caudal fin ; the anals were double, 
and the caudal was long and diphycercal ; the pectorals 
had a blserial arrangement of cartilaginous rays, and the 
ventrala were shark-like ; the teeth had two divergent 
'>n-^ and an intermediate denticle. The species lived 
during the Carboniferous and Permian periods. 
Pieuracanthini (plo''ra-kan-tlri'm), n. pi. [NL., 
< Pleiirai-initltiis + -int.'] An order of fishes 
otherwise called Xenacanthini and Ichthyotomi. 
See XenaeaiitMni. 
pleuracanthoid (plo-ra-kan'thoid), a. and . 
I. a. Of or resembling the Pleuracanthidte. 
II. . A member of the family Pleuracan- 
thidte. 
Also pleuracanth. 
Pleuracanthus (p!6-ra-kan'thus), n. [NL. 
(Agassiz, 1837), < Qr. ntevpfa, a rib, + anavda, 
spine.] A remarkable extinct genus of fishes, 
typical of the family Pleuracanthidse. 
pleural 1 (plo'ral), . [< pleura 1 + -al.] Of or 
pertaining to a pleura or the pleurae: as, the 
^>tewraZinveBtment of the lungs; the pleural cav- 
ity ; pleural effusion or adhesions. AlsopteunV. 
pleural 2 (plo'ral), a. [<pleuni + -al] 1. Per- 
taining to a rib or a pleurou, or to the ribs or the 
pleura collectively; costal; situated on the side 
of the thorax or chest. 2. Lateral, in general ; 
situated on the side of the body: correlated 
with dorsal, ventral, etc. 3. In arthropods, 
pertaining to an arthropleura or pleurite: ap- 
plied to the lateral limb-bearing section of an 
arthromere, between the steniite and the ter- 
gite. See cuts under Brachyura and Trilobita. 
4. Especially, in entom., lateral and thoracic : 
as, a pleural sclerite ; a pleural segment of a 
thoracic somite Pleural facet of the movable pleu- 
ra of a crustacean, the anterior part of a pleuron which is 
overlapped by the preceding pleuron In flexion of the body. 
- Pleural spine, a spine connected with a pleirroid. G. 
Kaur. 
pleuralgia (pltf-ral'ji-ft), n. [NL., < Gr. n-Any^s, 
the side, + aAyof, pain.] Pain in the pleura or 
side; pleurodynia. 
pleuralgic (pljj-ral'jik), a. [< pleuralgia + -ic.] 
Pertaining to or affected with pleuralgia. 
pleuralia (plH-ra'li-a), . pi. [NL., neut. pi. of 
"plcttralis, < Or. vfavpa, the side: see pleural 1 , 
pleura!.] In sponges, spicules forming a fur. 
F. E. Shulse. 
pleurapophysial (plo-rap-o-fiz'i-al), a. [<plcu- 
rapopnysis + -al.] Having the morphological 
character of a pleurapophysis ; of the nature of 
a rib; costal; costiferous. 
pleurapophysis (plo-ra-pof'i-sis), n. ; pi. plen- 
rni>i>j>hyses (-sez). [NL., < Gr. ir^cvpAv, a rib, 
+ aTo^wif, a process: see apophysis,] A lat- 
eral process of a vertebra, having the morpho- 
logical character of a rib, or forming a true rib. 
Such processes in the thoracic region of the spine are com- 
monly highly developed, and movably articulated forthwith 
the centra and with the diapophyses of the thoracic verte- 
bra, and they are then ribs in an ordinary sense. They are 
mostly rudimentary in other parts of the spinal column, 
but sometimes are very evident, as in the cervical ribs of 
various vertebrates, including man. In man, in the neck, 
they bound the vertebrarterial foramen in front, and pro- 
duce the tubercles known as anterior on the transverse 
process. Pleurapophyses are also by some considered to 
be represented in the lateral mass of the human sacrum. 
I i-v doped and movably articulated pleurapophyses, form- 
ing true ribs, often extend into the sacral as well as cervical 
region, as in various birds; and in all of this class more 
or fewer of them bear accessory processes called uncinate. 
(See cut under epipteura.) In serpents they run in un- 
broken series from head to tail, and assist in locomotion. 
(See ijastrosteye.) In some reptiles they support a pata 
glum (see cut under drai/nn) ; in the cobra they spread the 
hood. In Owen's nomenclature the term pteurapaphysin 
is restricted to the true bony part of a rib, the gristly part 
or costal cartilage being called he-mapuphysis. See cuts 
under vertebra and endoftkeleion. 
pleurarthron (pli?-rar'thron), .; pi. pleurar- 
Ilirn (-thra). [NL. ? < Gr. ir/.fvpd, a rib,+ aptipov, 
a joint.] "The articulation of a rib. Thomatf, 
Mr.l. Diet, 
pleurecbolic (plo-rek-bol'ik), a. [< Gr. n^cvpd, 
the side, + h.3o/r/, a throwing out: gee ecbolic.] 
Kvorsible or capable of protrusion by a forward 
movement of the sides of the containing tube, 
as an invert : correlated with acrembolic, and 
distinguished from pleurembolic. [Bare.] 
It is clear that, if we start from the condition of full 
eversion of the tube and watch the process of introversion, 
we shall mid that the plmrecbnlic variety is introverted 
by the apex of the tube sinking inwards. 
iMnkenter, Encyc. Brit, XVI. 652. 
pleurembolic (plS-rem-bol'ik), a. [< Gr. vhvpa, 
thf side, + tii.io/i/, :i putting into: see embolic.] 
45.-.:, 
Introversible or capable of being withdrawn 
by a backward movement of the parts into 
which it sinks, as an evert: correlated with 
acrecbolic, and distinguished from pleurecbolic. 
[Bare.] 
It [the pleurecbolic variety of everaton) may be called 
acrembolic, whilst conversely the acrecbolic tubes are 
plewmnbolie. Lanleetter, Encyc. Brit., XVI. 652. 
pleurenchyma (plB-reng'ki-mS), n. [NL., < Gr. 
K?vpd, the side, T tyxvp*, what is poured in : 
see enchymatous, parenchyma.] In bot., the 
woody tissue of plants. See wood-cell. 
pleurenchymatous (plo-reng-kim'a-tus), a. [< 
pteureiichynta(t-) + -out.] Of, pertaining to, 
or of the nature of pleurenchyma. 
pleuric (plo'rik), a. [< pleura* + -ic.] Same 
as pleural*. 
pleurisy (plB'ri-si), w. [Formerly &\aopluri#y, 
partly associated (as in the equiv. ML. plurior, 
pluritas, plethora) with L. plus (gen. pluris), 
more, as if implying a plethora of blood; < F. 
plcuresie = Pr. pleurezia = Sp. pleuresia = Pg. 
pleuriz = It. pleurisia, < LL. pleurisix, a later 
form of the reg. L. pleuritis: see pleuritis.] 
Inflammation of the pleura, it may be acute or 
chronic, and may or may not be accompanied by effusion. 
The effusion may be serous, seropurulent, purulent, or 
hemorrhagic. Also called pleuritit. 
The I'lfiiriar stabs him with desperate foyl 
Beneath the ribs, where scalding blood doth lioyl. 
Sylvester, tr. of Du Bartas's Weeks, 1L, The Furies. 
Virtue in a chafe should change her linen quick, 
Lest pleurisy get start of providence. 
Browning, King and Book, I. 1!4. 
Dry pleurisy, pleurisy without effusion, 
pleurisy-root (plo'ri-si-rot), . A plant of the 
milkweed family, Asclepiax tuberosa : so named 
Pleuroconchae 
side, + ppa-)xi (NL. branchue, sing, bronchia), 
gills.] A pleural gill ; a branchial organ borne 
upon an epimeron of any thoracic segment of 
a crustacean. Some of the thoracic segment*, a* in the 
crawfish, may bear on each aide four branch!*, a coxopo- 
dltic podohranchla, anterior and posterior arthrobran- 
chls?, and epimeral pleurobranchia 1 . 
Pleurobranchia- (i>18-ro-brang'ki-ft), . ;</. 
[NL., < Gr. v'Aevpa, the side, + lipajx' , Kills.] 
Same as Plevrolirancliinta. J. K. Gray, 1821. 
pleurobranchial (pl8-ro-brang'ki-al) ; a. [< 
pleurobranehia* + -al.] Of or pertaining to a 
pleurobranchia : as, a plrvrobranchial process. 
Pleurobranchiata (pl3-ro-brang-ki-a't), n.pl. 
[NL., neut. pi. of pleurowanchiatus : see pteu- 
robranchiateT] An order of opisthobrancniate 
gastropods, whose gills are tufts on the sides 
under a fold of the mantle, and which have gen- 
erally a spiral shell in the adult as well as the 
young. Also Pleurobranchia, Tectibranchiata. 
pleurobranchiate (pl8-ro-brang'ki-at), o. [< 
NL. pleurobranchiatvs, < Gr. ir/frpd, the side, + 
/}p6yxia, gills.] 1. Having pleurobranchise, as 
a crustacean. 2. Having gills along the sides: 
specifically, pertaining to the Pleurobranchiahi, 
or having their characters. 
Pleurobranchidse (pl8-ro-brang'ki-de), n. pi. 
[NL., < Plfurobranchus + -i<l.] A family of 
notaxpidean nudibranchiate gastropods, typi- 
fied by the genus Plcurobranchu,*. They have dis- 
tinct b'uccal tentacles forming a veil, bronchia on the 
right side of the lm.lv under the border 
of the mantle, a proboscidlfonn mouth, 
and numerous falciform marginal teeth 
on the nulu In. 
Pleurobranchus (plo-ro-lrang'- 
kus), n. [NL., < Gr. jrmyxi, the 
side, + ftpajx"*, gills.] A genim 
of nudibranchiatcs, typical of the 
family Plfurobrancktiup. 
Pleurocarpi (plo-ro-kiir'pi), . pi. 
T/fi'pd, the side, + tiapxof, fruit.] A divisinn 
of bryaceous mosses in which the fructification 
is lateral on the stems, having proceeded from 
the axils of the leaves. Sometimes called 
Plfitrocarpse. 
pleurocarpous (plo-ro-kiir'pus), n. [< Gr. 
ir/.ii>pA, the side, + ipn-of, fruit.] In bot., hav- 
ing the fructification proceeding laterally from 
the axils of the leaves, BH in some mosses. 
[NL., < Gr. 
i. Part of the Inflorescence of Pleurisy-root (Ai<ltfiat rultrosa. 
2. The root ami the lower uart of the stein, a, a flower : ^, the anther 
and the &ti|pu.i ; < , the fruit ; </, a seed. 
from its medicinal use. Also called butterfly- 
vxed. 
pleurite (plo'rit), n. [< Gr. ir/^vpd, the side, 
+ -ife 2 .] 1. In arthropods, a pleural sclerite; 
a lateral piece or segment of a somitic ring or 
somite, between the tergite and the sternite. 
2. In a restricted sense, the lateral or pleural 
part of an abdominal segment of an insect. 
pleuritic 1 (pltf-rit'ik), a. [< Ij.pleuriticus, < Gr. 
ir/fiyxm-of, suffering from pleurisy, < irfavpirif, 
pleurisy: see pleuritis.] 1. Pertaining to or 
suffering from pleurisy : as, pleuritic symptoms 
or affections; a pleuritic patient. 2. Causing 
or bringing pleurisy. 
For while the effluence of the skin maintains 
Its native measure, the pleuritic Spring 
Glides harmless by. 
Armstrong, Art of Preserving Health, iii. 
pleuritic 2 (plij-rit'ik), a. [< plfurite + -ic.] 
1. In arthropods, of or pertaining to a pleu- 
rite; pleural, as a segment of a somite. 2. 
In iitnin.. specifically, lateral or pleural and 
abdominal ; of or pertaining to a pleurite. 
pleuritical (plij-rit'i-kal), a. [< pleuritic* + 
-al.] Same as pleuritic*. 
pleuritis (pl^-ri'tis)^ n. [NL., < L. pleuritic, < 
Gr. ir't.tvplris, pleuritis (cf. ir?jvpiTtit, on or at the 
side), < vtevpa, the side: see pleura*.] Same 
as pleurisy. 
pleuroblastic (plo-ro-blas'tik), a. [< Gr. virv- 
pa, the side, + /J^oorof, a germ.] In hot., in 
the Peronottporeee, producing vesicular lateral 
outgrowths which serve as haustoria. De Bary. 
Pleurobrachia(plB-ro-bra'ki-ft), n. [NL., < 
Gr. 7r/.rvpa, the side, + ,)paxi<jv, the arm.] A 
genus of ctenophorans : same as Cydippe, 1. 
pleurobranchia 1 (pl8-ro-brang'ki-aj, w.; pi. 
pleuriiliniiiclii.r (->). [NL.. < (Jr. rfjvpa, tne 
pleurocele (plo'ro-sol), w. [< Gr. irfarpa, the 
side, + x^i, tumor.] Same as pucumocele. 
pleurocentral (plo-ro-sen'tral), a. [< pleuro- 
centrum + -al.] Of or pertaining to a pleuro- 
centrum ; heniicontral. 
pleurocentrum (plo-ro-sen'trum), n.; p\.pleu- 
roceiitra(-tTH). [NL., < Gr. ir}*vpa, the side, + 
anrpov, the center.] One of the lateral ele- 
ments of the centrum of a vertebra; a hemi- 
centnim. 
Pleurocera (pl^-ros'e-rii), n. [NIj., < Gr. irf.evpA, 
the side, + Ktpar ; , horn."] A genus of American 
fresh-water univalves, typical of the family 
Pleuroceridie. Also called Trypanogtonia. 
pleurocerebral (plo-ro-ser'e-bral), a. [< Gr. 
TtfavpA, the side, + L. cerebrum, 'the brain: see 
cerebral.] Connecting the side of the body with 
the head: specifically, in mollusks and some 
other invertebrates, noting a nervous cord con- 
necting a cerebral with a pleural ganglion. 
Pleuroceridae (plo-ro-ser'i-de), n. pi. [NL., < 
Pleurocera + -idtr.] A family of tatnioglossate 
gastropods, typified by the genus Pleuroora . 
It comprises a great number of species, mostly occurring 
In the fresh waters of the I'ultea States, referred by the 
old writers to the melanians. They are distinguished, 
however, by their unfringed mantle, want of a distinct 
male organ, and oviparity. Also called Ceriphnnida and 
Strepomatidje. 
pleurocoele (pl8'ro-sel), n. [< Gr. ntevpa, the 
side, + noi)jov, a hollow, neut. of xoiAof, hollow.] 
One of two lateral spaces of the posterior part 
of the splanchuoco?le of a brachiopod. 
I propose to give the name pUumcaeUs to theae spaces, 
simply from their position as aide chambers. 
Daeidton, Trans. Linn. Soc., XIV. III. 210. 
pleurocolic (pld-ro-kol'ik), a. [< Gr. 
a rib, + L. colon, colon: see oo/on 2 .] Same 
as eostocolic Pleurocolic ligament. Same as onto- 
colie ligament (which see, under cwrfocofic). 
pleUTOCOllesis (plO'ro-ko-le'sis). n. [NL., < 
Gr. T/fi'pu, the side, + KO/>JTO/{-, a gluing, < 
v<//r, glue, < k6/'/a, glue.] Adhesion of the 
pleura. 
Pleuroconchaet (plo-ro-kong'ke), n.pl. [NL.. 
< Gr. 77/Myxi. the side, + (to) x'l, a muissel, shell.] 
A suborder of inequivalvr ' /. compris- 
ing the families Aririiliilir. J'ci-lhiiila, Sjiiinili/- 
lidie, ()srreid&, and Chamidfe. 
