petrel 
ckickeia, are the very small sooty species like ProctUaria 
pelayica, though of several genera, Including Frocellarto 
(formerly culled Thaia**idrmna\ Cymochorea, Ualocyp- 
t>'fi, find Octanites, '1'hu most numerous species to which 
the name is given are those of the genera <K#trelata, Dap- 
(ion, and soim- others, such as the capped petrel, Wxtrelata 
hasttata, and the Cape- pigeon, DflfWum capen#e. These 
-^- 
Stonny Petrel (Protrllaria ftlagica). 
are of medium size, or ratlier small, and almost exclusive- 
ly Inhabit southern seas. Petrels of the large genus Pvf- 
fnwt are commonly known as thearwaten and haadeni. 
The large gnll-like petrels of the genus Fulmarus ana some 
related genera are called fulmars. All are pelagic, and 
practically independent of land except during the breed- 
ing-season. They breed for the most part in burrows or 
holes in rocks by the seaside, laying a single white egg. 
Many of them arc wont, like albatrosses, to follow ships 
for many days at sea, to feed upon the refuse of the cook's 
galley, and may sometimes be taken with hook and line. 
In powers of long-sustained flight they surpass all other 
birds, but, with the exception of one genus (Ptlecaaaidei 
or Halodroma), they cannot dive. See also cuts under 
Daption, fulmar, haijden, and (Estrelata. 
2. The kittiwake, a gull. [Flamborough Head, 
Eng. 1 _ pintado petrel. See pintado. 
petrel 2 t, An obsolete form of poitrel. 
petrenelt, . An obsolete variant otpetronel. 
petrescence (pe-tres'ens), n. [< petrescen(t) + 
-ce.] Petrifaction. Maunder. 
petrescent (pe-tres'ent), a. [< L. petra, < Gr. 
xfrpa, rock, +' -escen'i.] Possessing the proper- 
ty of changing or converting into stone ; petri- 
fying- 
Springs of petreicent water. Boyle, Works, III. 654. 
Petricola (pe-trik'6-la), . [NL. : seepetrico- 
lous.] The typical genus of Petricolidee. La- 
marck. 
Petricolidse (pet-ri-kol'i-de), n.pl [NL., < Pe- 
tricola + -idle.] A family of bivalve mollusks 
which live in rocks, named by D'Orbigny in 1837 
from the genus Petricola; the rock-borers. They 
a, Pttritela (Pttricolaria) fholadtfartnii (right valve). #, Petri- 
cola litkofhaga (right valve). 
are related to the Veneridtc, but the mantle is enlarged, 
the pedal opening small, the foot small, and the shell more 
or less gaping. The species for the most part perforate 
clay or soft rock. 
petricolous (pe-trik'o-lus), a. [< NL. petrieo- 
la, < L. petra ('< Or. ntrpa), a rock, + colere, in- 
habit.] Inhabiting rocks ; saxicoline; lithodo- 
mous, as a mollusk. See cuts under date-shell, 
l'i tricolldx, and piddock. 
petrifaction (pet-ri-fak'shon), n. [< L. as if 
*petrifactio(n-), < petra (< Gr. irfrpa), rock, + 
factus, pp. of facere, make. Cf. petrify.] 1. 
Conversion into stone, specifically of organic 
substances or parts of such ; fossilization ; re- 
placement of organic matter by some mineral 
substance, in which process more or less of the 
form and structure of the organized body is pre- 
served. 2. An organic substance converted 
into stone; a fossil. The words petrifaction and fossa 
are entirely synonymous at the present time. Formerly 
fossil was applied to minerals or mineral substances dug 
from the earth, whether they did or did not exhibit any 
traces of organic structure. See/oggtf. 
3. Figuratively, a rigid or stunned condition 
resulting from fear, astonishment, etc. 
petrifactive (pet-ri-fak'tiv),a. [< petrifaction) 
-t- -ive.~\ 1. Of or pertainiug to petrifaction. 
Xir T. Kroirnc. 2. Having power to petrify or 
to convert vegetable or animal substances into 
stone. 
petrifiable(pet'ri-fi-a-bl),a. [< petrify + -able.] 
Capable of being petrified. 
petriflc (pe-trif'ik), a. [= Sp. petriftco = Pg. 
It. prtrifu-o, < L. as if *petriticus, < petra, rock, 
+ faeere, make. Cf. petrify.] That converts or 
has power to convert into stone. 
4427 
The aggregated soil 
Death with his mace petnjlc, cold and dry, 
As with a tridrnt, smote, and fix d as firm 
As Delos, floating once. Milton, K L., x. 294. 
Not the wlng'd Perseus, with Petrifck Shield 
Of Gorgon's Bead, to more Amazement charm 'd his Foe. 
Congreve, On the Taking of Xamurc. 
petriflcatet (pet'ri-fi-kat), t'. t. [< L. pi-t,-(ti- 
I'dtiix, jip. of "/i> li'iiii'iii-i 1 , petrify: see petrify.] 
To petrify. /. Hall, Poems, p. 96. 
purification (pet ri-fi-ka'shon), n. [< F. pftri- 
fication Sp. pi'trijicacioii = Pg. petrificai;flo 
= It. pelrijii'ii-inni', < L. as if 'petrificatio(n-), 
< "prtrififiirr, petrify: see petrify.] 1. Same 
as iiclrijarliiiii. Xi? T. Browne, Vulg. Err., ii. 3. 
2f. Obduracy; callousness. [Rare.] 
It was observed long ago by F.pictetus that there were 
some persons that would deny the plainest and most evi- 
dent truths ; and this state and condition he terms t pet- 
rijicatiim or mortification of the mind. 
lliMnu'M, Melamprousea, p. 1. (Latham.) 
petrify (pet'ri-fi), r. ; pret. and pp. petrified, 
ppr. petrifying. [< F. petrifier = Sp. Pg. petri- 
ficar = It. petrificare, < L. as if "petrificare, < 
petra (< Gr. ntrpa), rock (see pier), + facere, 
make. Cf. petrific.] I. trans. 1. To convert 
into stone or a stony substance ; change into 
stone. 2. To make hard as stone ; render hard 
or callous : as, to petrify the heart. 
Full In the midst of Euclid dip at once, 
And petrify a genius to a dunce. 
Pope, Dunciad, Ir. 264. 
3. To paralyze or stupefy as with fear or amaze- 
ment : as, to petrify one with astonishment. 
The poor petrified journeyman, quite unconscious of 
what he was doing in blind, passive self-surrender to 
panic, absolutely descended both flights of stairs. 
De Quincry. 
Suddenly two men with guns came out of the woods, 
but at the sight of the flatboat stood petrified. 
Q. W. Cable, Stories of Louisiana, vii. 
II. intrans. To become stone or of a stony 
hardness, as organic matter by means of cal- 
careous or other deposits in its cavities; hence, 
to change into lifeless hardness or rigidity. 
Like Niobe we marble grow. 
And petrify with grief. 
Dryden, Threnodia Augustalls, 1. 8. 
petrinalt, An obsolete form of petronel. 
Petrine (pe'trin), a. [< LL. as if "Petrinus (cf. 
ML. petrinus, < Gr. irtrpivos, of rock), < Petrus, < 
Gr. Ilfrpof, Peter : see petrel 1 .] Of or pertain- 
ing to the apostle Peter or his doctrines or writ- 
ings : as, the Petrine epistles. See Petrinism. 
Petrine liturgy, the Roman liturgy attributed by eccle- 
siastical tradition to Peter. 
Petrinism (pe'trin-izm), n. [< Petrine + -ism.] 
The beliefs or tendencies attributed to the apos- 
tle Peter; according to the Tubingen school of 
theology, the doctrine that Christianity is a 
Ehase or development of Judaism, supposed to 
ave been advocated by the followers of Peter: 
opposed to Paulinism. See Paulinism, and Tu- 
bingen school (under school). 
A purely speculative process of conflicting tendencies, 
which started from an antagonism of Petrinism and Pau- 
linUm. .*A"/, Hist Christ Church, I. 7. 
petrograph 
', a swallow: see clielidon.] A genus 
of HirundinitUe, contiiijiiiiganumberof sp' 
of various parts of the world, which affix nests 
of mud to rocks, whence the name; the eliff- 
swallowg. /'. lunifrimt is the common cliff-swallow, 
caves-swallow, or mud-swallow of the United HtaU's, which 
builds clusters of bottle-nosed nests made of little pellets 
of mud stuck together. See cuts under eavtt-ncalloic and 
hive-nest. 
petrodrome (pet'ro-drom), n. An insectivorous 
mammal of the genus Petrodromus, P. tetradac- 
tylus, of Mozambique. 
Petrodromus (pet-rod'ro-mus), n. [NL. (W. Pe- 
ters, 1846), < Gr. xtrpa, rock, jrtTpof, a stone, + 
fpafulv, aor. inf. of rpixetv, run.] A genus of 
elephant-shrews of the family Macroscelidid, 
Petrodrome (Petrutromm utradactyltts). 
differing from the genus Macroscelides in hav- 
ing the hind feet with only four toes. The type 
is P. tetradactylus. See also cut under elephant- 
shrew. 
Petroff 's defense. In chess-playing. See open- 
ing, 9. 
Petrogale (pet-rog'a-le), n. [NL., < Gr. irerpn. 
rock, irtrpof, a stone, + vaX^, ya^i?, a weasel.] 
1. A genus of marsupials of the family Macro- 
podidfe, founded by J.E. Gray in 1837; the rock- 
kangaroos. There are six or more species, all Austra- 
lian, of which the brush-tailed wallabee, P. penicillatut, 
Petrobieae (pet-ro-bi'e-e), n. pi. [NL. (Bentham 
and Hooker, 1873), < Petrobium + -e&.] A sub- 
tribe of composite plants of the tribe Helian- 
thoidex, characterized by the dioecious chaffy 
heads, each with rudimentary styles or anthers. 
It includes three genera, two of South American 
shrubs, and one a tree, Petrobinm (the type). 
Petrobium (pet-ro'bi-um), n. [NL. (R. Brown, 
1817), so called in allusion to its home on the 
rock of St. Helena; < Gr. irtrpa, rock, + /3)f. 
life.] A genus of composite plants, type of 
the subtribe Petrobiete, having a flat receptacle 
and linear awned aehenia. There is but one species, 
a small tree, found only on the island of St. Helena, bearing 
toothed opposite leaves, and small heads of yellow flowers 
in leafy panicled corymbs at the summits of the branches. 
It is sometimes known as root-plant of St. Helena, and on 
the island as whiteirood. Its remarkably recurved tubular 
corollas make the head of flowers at first seem radiate. 
Petrobrusian (pet-ro-brS'si-an), n. [< ML. 
Petrobnisiani, pi., < Petrus Br'vsius (Pierre de 
Bruys) (see def.) + -an.] One of the followers 
of Peter (Pierre) de Bruys, especially numerous 
in the south of France in the twelfth century. 
De Bruys opposed church buildings, bishops, priests, and 
iHTfinonials, and rejected transubstantiation and infant 
baptism. 
petroccipital (pet-rok-sip'i-tal), a. [<pe<r(o) 
+ occipital.] Of or pertaining to the occipital 
bone and the petrous part of the temporal bone : 
as, the petroccipital suture. Alsopetro-occipital. 
See cut under craniofacial. 
Petrpchelidon (pet-ro-kel'i-don), n. [NL. (Ca- 
banis, 1851), < Gr. mrpa, rock, xfrpof, a stone, 
Yellow-footed Rock-kangaroo (Pttrogalt xantftofMj\ 
and the yellow-footed rock-kangaroo, P. xanthoput, are 
examples. These kangaroos are fitted for living among 
rocks, where they display great agility. The hind limbs 
are less disproportionate than in other kangaroos, and the 
tail is used less in supporting the body or in leaping. 
2. ( '. <'.] An animal of this genus. 
petrogeny (pet-roj'e-ni), n. [< Gr. irtrpa, rock, 
ircrpof, a stone, + -ytvcia, < -yevf/c, produced: see 
-geny.] The science of the origin of rocks; 
theoretical petrography or petrology : a word 
little used, and bearing the same relation to 
petrography or petrology which geogetiy does to 
geology. 
petroglyph (pet'ro-glif), n. [< Gr. irtrpa, rock, 
Ktrpos, a stone, + y^vfy, carving: see glyph.] A 
carving on or in stone ; a rock-carving. 
petTOglyphic (pet-ro-glif 'ik), a. [< petroglyph-y 
+ -ie.] Of or pertaining to petroglyphy: as, 
a petrogiyphic inscription. 
petroglyphy (pet-rog'li-fi),n. [<Gr.^rpa,rock, 
vtrpof, a stone, + fMfuf, carve, sculpture.] 
The art or operation of carving inscriptions and 
figures on rocks or stones. 
petrograph (pet'ro-graf), H. [< Gr. verpa, rock, 
vtrpof, a stone, + jpafeiv, write.] A writing on 
a rock ; a petroglyph. [Rare.] 
Mr. Cushlng's party found on the rocks of neighboring 
mountains petmrrapht, or crude etchings. 
Science, XII. 40. 
