Chelonia 
long periods without food. Some, however, are quite 
active. They are oviparous. Most of the species are car- 
nivorous and predatory, but the true land-tortoises are 
mainly herbivorous. There are over 200 species, among 
them a few gigantic ones, as the tortoises of the Galapagos 
and Mascareue islands : one of the fossil species is said to 
have been about 20 feet long. The living genera are very 
numerous. The Chelonia are variously subdivided. They 
were formerly generally distributed among four families, 
the club-footed land-tortoises, the related fresh-water tor- 
toises, the soft tortoises, and the sea-turtles. Huxley called 
these four groups Teshulinea, Etnydea, Trionychoidea, and 
Euereta. These groups have, however, been long discarded, 
and the species are now segregated among many families 
which have been variously combined. Most of the species 
of the southern hemisphere belong to a peculiar old-fash- 
ioned group, the pleurodirous, while those of the northern 
are cryptodirous. Also Chelonides, Chelonii. 
2. [Used as a singular.] Same as Chelone, 1. 
chelonian (ke-16'ni-an), a. and n. [< Chelonia 
+ -aw.] I. a. Of, pertaining to, or having the 
characters of the Chelonia; testudinate. 
II. n. One of the Chelonia or Testudinata ; a 
turtle or tortoise. 
chelonid, cheloniid (kel'o-nid, ke-16'ni-id), B. 
A tortoise of the family Chelonidce. 
Chelonidse, Cheloniidse (ke-lon'i-de, kel-o-m'- 
i-de), n. pi. [NL., < Chelone, Chelonia, 2, + 
-idee. ] A family of marine Chelonia, having the 
fore limbs longer than the hind, and converted 
into paddles or flippers for swimming by the 
union and webbing of the digits ; the sea-tur- 
tles, or turtles proper. Its type is the genus Chelone 
or Chelonia, containing the green turtle (C. midas) and the 
hawk's-bill turtle (C. imbricata). Another leading form 
is the loggerhead, Caouana (or Thalassochelys) cttretta. 
Formerly the Dermatochelyg (or Sphargis) coriacea was 
referred by some to the family, but it has long been uni- 
versally isolated as the representative of a very distinct 
family (Dermatochelyidce or Sphargididoz), and even sub- 
order (Athecte). The green turtle and the loggerhead are 
known to hybridize, the progeny being known to the fish- 
ermen as the bastard turtle, and having the scientific name 
of Colpochelys tempi. The group is the same as Euereta 
(which see). See turtle. 
Chelonides (ke-lon'i-dez), n. pi. [NL. (Swain- 
son, 18_39). < Chelone.] Same as Chelonia, 1. 
Chelonii (ke-16'ni-I), n. pi. 1. Same as Che- 
lonia, 1. 2. A suborder of Testudinata, com- 
prising all the land and fresh-water forms. 
Oppel; Agassiz. 
Cheloniidae, n. pi. See Chelonidce. 
chelonite (kel'o-nit), n. [NL., < Gr. ^t/laiio?, a 
tortoise, + -ite 2 .] A name of certain fossil sea- 
urchins of the family Cidaridce. 
Chelonobatrachia (ke-lo"no-ba-tra'ki-a), n. pi. 
[NL., < Gr. xeAuvr/, tortoise, + /JdTpa^of,"a frog.] 
Same as Anurcft. 
Chelonography (kel-o-nog'ra-fi), n. [< Gr. x e - 
TMVTI, a tortoise, + -ypaijila, < ypdfynv, write.] A 
treatise on turtles ; a description of chelonians. 
chelonologist (kel-o-nol'6-jist), . [< chelonol- 
ffy + -tit.] One Versed in the study of the 
chelonians. 
chelonqlogy (kel-o-nol'p-ji), n. [< Gr. xtMnm, 
a tortoise, + -toyta, < 2.~yetv. speak : see -ology.] 
That branch of zoology which relates to the 
chelonians or tortoises. 
Ghelonura (kel-o-nu'ra), n. [NL. , < Gr. x&foy, 
tortoise, + oiipd, tail.]' Same as Chelydra. 
Chelophora (ke-lof'o-ra), n. pi. [NL., < Gr. 
Xn^l, a hoof, claw, talon, + -<t>6pof, -bearing, < 
<t>pew= E. bear 1 .'] A series of deciduate mam- 
mals with a zonary placenta, consisting of the 
orders Proboscidea and Hyracoidea. The word is 
scarcely used, except to distinguish these two orders col- 
lectively from the Carnivora, all three forming the Zono- 
placentalia. 
Chelsea porcelain. See porcelain. 
Chelura (ke-lu'ra), n. [NL., < Gr. yrp^ claw, 
+ oiipd, tail.] A 
genus of amphi- 
pod crustaceans, 
typical of the 
family Cheluridce 
or wood-shrimps. 
Boring \mphipod (Clitlur-aterttrans}, C. terebrans gnaws 
magnified. into submerged 
(From Report of U. S. Fish Commission.) Wood, and is one of 
946 
the most destructive crustaceans, owing to its immense 
numbers, though it is of diminutive size, being only about 
a third of an inch long. 
Cheluridae (ke-lu'ri-de), n. pi. [NL., < Chelura 
+ -idee.] A family of amphipods, represented 
by the genus Chelura, having several of the ab- 
dominal segments united, and much modified 
abdominal limbs ; the wood-shrimps. They bore 
tunnels beneath the surface of subniergedT wood, and are 
nearly as destructive to timber as the ship-worm. 
chelyt (ke'li), n. An obsolete form of chela 1 , 
1 and 2. 
It happeneth often, I confesse, that a lobster hath the 
chely or great claw of one side longer then the other, but 
this is not properly their leg, but a part of apprehension. 
Sir T. Browne, Vulg. Err., iv. 5. 
Chelydse (kel'i-de), n. pi. Same as Chelydidce. 
Chelydidae (ke-lid'i-de), . pi. [NL. (properly 
Chelyidce), < Chelys + -idee.] A family of pleu- 
rodirous Che- 
lon ia, typified 
by the genus 
Chelys. The 
head is not com- 
pletely retrac- 
tile, and is much 
depressed; ithas 
very large tem- 
poral muscles, 
and is covered 
with soft skin, 
which on the Matamata (Chelys matamata}. 
beak takes the 
form of broad, fleshy lips. The matamata, Chelys mata- 
mata, is the representative of the family. Also Chelididce, 
Chelyidae, Chelyoidce. 
chelydoid (kel'i-doid), a. and n. [Properly 
chelyoid, < Chelys + -oid. Of. cheloid^.] I. a. 
Pertaining to or resembling the Chelydidce. 
Also chelyoid, cheloid. 
II. . A tortoise of the family Chelydidce. 
It may be seen from this list that no Chelydoid passes 
northward beyond the Isthmus of Panama. 
Giinther, Encyc. Brit., XX. 471. 
Chelydra (kel'i-dra), n. [NL., < Gr. x&vfpos, 
an amphibious serpent, also a kind of tortoise.] 
The typical genus of the family Chelydridce. c. 
serpentina is the common snapper or snapping-turtle of 
America. Also Chelonura. See cut under alligator-ter- 
rapin. 
Chelydradse (ke-lid'ra-de), n. pi. [NL., < 
Chelydra + -adce.] A group of cryptodirous 
tortoises in Gray's system, including the Che- 
lydridce and the Cinosternidce of other authors. 
Chelydridse (ke-lid'ri-de), n. pi. [NL.. < Che- 
lydra + -idee.] A family of tortoises, typified 
by the genus Chelydra, having a long tail, large 
non-retractile head, and a long neck, it embraces 
the two largest fresh-water chelonians oftheTJnitedStates, 
the snapping-turtle (Chelydra serpentina) and the alliga- 
tor-turtle (Macrochelys lacertina). Also spelled, improp- 
erly Chelidridae. 
Chelydrinse (kel-i-dri'ne), n. pi. [NL., < Chf- 
lydra + -ince.] A subfamily of tortoises, typi- 
fied by the genus Chelydra : same as the family 
Chelydridce. 
chelydroid (kel'i-droid), a. and n. [< Chelydra 
+ -oid.] I. . Pertaining to or resembling the 
Chelydridce. 
II. re. A member of the family Chelydridce. 
chelydron (kel'i-dron), n. [NL., < Gr. xfavtpoc. : 
see Chelydra.] A turtle of the genus Chelydra 
or some related genus ; an alligator-tortoise. 
Chelyetes (ke-li'e-tez), n. [NL., < Gr. x&vt, a 
tortoise, + ( f) crr/f, a kinsman, neighbor.] The 
typical genus of mites of the family Chelyetidce. 
Chelyetidse (kel-i-et'i-de), n.pl. [NL., < Che- 
lyetes + -idee.] A family of mites, with the 
skeleton composed of sclerites embedded in a 
soft skin, stigmata near the rostrum, and legs 
of five joints, the first pair being tactile organs. 
They are remarkable for the enormously developed palpi 
and sharp rostrum, well suited for plunging into the body 
of their victims, upon whose juices they subsist. The fam- 
ily contains predatory species, such as Chelyetet parasiti- 
rnrax, C. heteropalpwi, etc., which it has been shown are 
strictly parasitic, although with a form of parasitism not 
contemplated in Van Beneden's classification, namely, a 
parasitism beneficial to the host, as the guest lives upon 
other parasites which are injurious to the host. Michael. 
Chelyidae (ke-U'i-de), n. pi. Same as Chelydidce. 
chelynget, An old form of keeling. 
chelyoid (kel'i-oid), n. The proper form of 
chelydoid. 
Chelyoidse (kel-i-oi'de), n. pi. Same as Chely- 
didce. 
chelys (kel'is), n. [< Gr. ^eAvf, a tortoise, a 
lyre, the constellation Lyra. Cf. Chelone.] 1. 
The ancient Greek lyre : so called because first 
made of tortoise-shell. 2. In the sixteenth and 
seventeenth centuries, a lute or viol. 3. [cup.'] 
[NL.] A genus of tortoises, the type of the fam- 
ily Chelydidce, containing only one species, C. 
matamata or C. finibriata. See matamata, and 
cut under Chelydidce. 
chemical 
cheme (ke'me), n. [LL. cheme, ML. chema, a 
measure for liquids, L. chema (Pliny), a gaping 
mussel, < Gr. x'/Plj a yawning, a shell, a cockle, 
a measure, < \/ *x a in X" aiiflv t X a ' vc ' v > gape : see 
chasm, chaos.] A Roman weight, equal to about 
35 grains troy. 
chemic (kem'ik), a. and n. [Also recently 
chemick, early mod. E. chimic, chimick, chymic, 
chymick; after F. chimique = Sp. quimico = Pg. 
It. chimico, < ML. *chemicus, *chimicus, < chimia, 
chemistry: see chemy, alchemy.] I. a. 1. Per- 
taining to chemistry (or, formerly, to alchemy) : 
same as chemical, but now used chiefly in poetry. 
Analysis is carried into everything. Even Deity is sub- 
jected to chemic tests. Lowell, Fireside Travels, p. 169. 
The wicked broth 
Confused the chemic labour of the blood. 
Tennyson, Lucretius. 
2f. Imitative ; adulterated ; not the genuine 
thing. See alchemy, 3. 
World, thou'rt a traitor ; thou hast stamp'd thy base 
And chymie metal with great Cxsar's face. 
Quarles, Emblems, ii. 5. 
II. n. If. A chemist or an alchemist. 
Chimicho [It.], a chimicke or an alchimist. Florio. 
2. In bleaching, a dilute solution of ehlorid of 
lime. 
Chloride of lime is generally termed cheinick in the dye- 
house. . . . There is the danger of rotting the cloth when 
very strong chemick is employed. 
W. Crookes, Dyeing and Calico-printing, p. 49. 
Blue Chemic. Same as chemic blue (which see, under 
blue, n.). 
chemic (kem'ik), v. t. ; pret. and pp. chemicJced, 
ppr. chemicking, [< chemic, n., 2.] In bleach- 
ing, to steep, as cotton goods, in a dilute solu- 
tion of ehlorid of lime in stone vats, the liquor 
being pumped up and strained through the 
goods until the action is complete. 
chemical (kem'i-kal), a. and n. [Earlier chym- 
ical; < chemic + -al. See chemistry.] I. a. 1. 
Pertaining to chemistry: as, a chemical experi- 
ment. 2. Pertaining to the phenomena with 
which chemistry deals and to the laws by which 
they are regulated ; accordant with the laws of 
chemistry. 
Not only do worms aid indirectly in the chemical disin- 
tegration of rocks, but there is good reason to believe that 
they likewise act in a direct and mechanical manner on 
the smaller particles. Darwin, Vegetable Mould, p. 246. 
Also chemic. 
Chemical acetlflcatlpn. See acetiftcation. Chemi- 
cal action. See action. Chemical affinity, elec- 
tive affinity, names formerly used for chemical force, and 
implying a property inherent in atoms of selecting other 
atoms with which to unite, or of preferring one combina- 
tion to another. Chemical analysis, the resolution of 
complex bodies into their elements. It is either quali- 
tative or quantitative. Qualitative analysis consists in 
the determination of the component parts merely as re- 
spects their nattire, and without regard to their relative 
proportions. Quantitative analysis consists in the deter- 
mination of the relative proportions of the components. 
Chemical black, bronze. See black, bronze. Chemical 
change, as distinguished from physical change, a change 
which destroys the identity of the substance affected. A 
physical change is manifested without loss of identity by 
the substance. Thus, a mass of copper may be reduced 
to fine particles, drawn into wire, melted and cast into in- 
gots or charged with electricity, without losing its identity 
as copper. But if copper is put into nitric acid, it dissolves 
and is converted into another substance, copper nitrate. 
The copper, in consequence, has lost its identity, and has 
undergone a chemical change. Chemical combination, 
the intimate union by chemical force of two or more ele- 
ments or compounds to form a new compound differing in 
properties from either of its constituent bodies. It differs 
from mechanical mixture in that each element of a chem- 
ical combination has a certain fixed and invariable com- 
bining proportion, whereas a mixture of substances can 
be made with varying amounts of its ingredients. In a 
mechanical mixture the particles of each of its ingredients 
can usually be identified and separated by mechanical 
means ; in a chemical combination the constituents are 
so blended that they cannot be identified. Thus, if chlo- 
rin and hydrogen gas are mixed in any desired propor- 
tion, the chlorin in the mixture will be evident by its char- 
acteristic color and odor. But if this mechanical mixture 
is exposed to strong light, a chemical conibination takes 
place rapidly between the two gases, with evolution of 
heat. They combine, however, only in exactly equal vol- 
umes, and if an excess of either is present it remains un- 
combined. In the new compound, hydrochloric acid, 
chlorin cannot be detected by either color or smell, nor 
be isolated except by chemical means. Chemical de- 
composition, the separation by chemical force of the 
component parts of bodies from one another, or the resolu- 
tion of bodies into their elements. Chemical equation, 
a symbolic expression used to represent a chemical reac- 
tion. The reagents, or bodies which enter into the reac- 
tion, form the left-hand member of the equation, and the 
resultants of the reaction form the right-hand member. 
Thus, the fact that calcium ehlorid and sodium carbonate 
when brought together in solution react on each other, 
forming calcium carbonate and sodium ehlorid, isexpressed 
by the following equation : 
CaCl 2 + NaoCO;, = ('aCO :l + 2NaCl. 
This is a true equation in the algebraic sense, because the 
value of the two members is the same. Since matter is 
indestructible, nothing is lost in the reaction, and the 
weights of calcium ehlorid and sodium carbonate which 
reacted must be precisely the same as the combined 
