TRI 
and hooked on one side ; gill membrane, 
seven-! ayed; body compressed and eiisi- 
forni ; tail subulate, and without fins. There 
are two species. T. argenteus, or the silver 
trichinre, is about two feet and a half lonv, 
and inhabits the lakes and riveis of South 
America, and of some parts of Asia. Its 
colour of a bright silver ; its body tapers 
gradually, and teiininates in an absolute 
point; its (jorsal fin extends nearly through 
the animal’^ whole length. It is a fish re- 
markable for its voracity, and has been 
known to leap into boats in quest of prey. 
It is used for the table. The T. eleetriens 
is of the same size with the former; but 
differs in several circumstances relating to 
the teeth, jaws, and tail. It is supposed to 
possess an electrical power. 
TRICHOCARPTJS, in botany, a genus 
of the Polyandria Digynia class and ordei'. 
Essential character ; calyx four or five- 
parted ; corolla none ; styles two, bifid ; 
capsule bristly, four-valyed, many-seeded. 
There is only one species, riz. T. laurifolia, 
a native of the woods of Guiana. 
TRICHOCEPHALUS, in natural his- 
tory, a genus of the Vermes Intestina class 
and order. Body round, elastic, and vari- 
ously twisted ; head or fore part much 
thicker, and furnished with a slender ex- 
sertilc proboscis ; tail or lower part long, 
capillary, and tapering to a point. Tliere 
are six species enumerated, and named 
^ om the animals in which they are found : 
T. hominis inhabits the intestines of sickly 
children, generally the cneciim, and in con- 
siderable numbers ; it is usually about two 
inches long, and in colour it resembles the 
ascaridesi The head is obtuse and fur- 
nished with a very slender proboscis, 
which it can eject or retract at pleasure ; 
tail, or thinner part, twice as long as the 
thicker end, and terminating in a fine hair- 
like point. T. equi found in the intestines 
of the horse ; there are others found in the 
intestines of the boar, fox, mouse, &c. 
TRICHODA, in natural history, a genus 
of the Vermes Infusoria. Worm invisible, 
pellucid, hairy, or horned. There are se- 
venty or eighty species in sections. A. 
hairy. B. furnished with pirri. C. horned. 
TRICHOMANES, in botany, a genus 
of the Cryptogamia Filices class and order. 
Ndtural order of Filices or Ferns. Generic 
character : fructifications inserted into the 
margin of the frond, separate; involucres 
urn shaped, undivided, opening outwards ; 
columns extending beyond the involucres, 
like styles. There are twenty-seven spe- 
cies, chiefly natives of the West Indies, 
TRI 
TRICHOSANTHES, in botany, a genu* 
of the Monoecia Syngenesia class and or- 
der. Natural order of Cucurbitaceae. Es- 
sential character : calyx five-toothed ; co- 
rolla five parted, ciliate : male, filament* 
three : female, style trifid ; pome oblong. 
There are seven species. 
TRICOSTEMA, in botany, a genus of 
the Didynamia Gymnospermia class and 
order. Natural order of Verticillatae or 
Labiatse. Essential character : corolla, 
upper lip sickle shaped ; stamina very long. 
There are three species. 
TRIDAX, in botany, a genus of the Syn- 
genesia Polygamia Superflua class and or- 
der. Natural order of Coinpo.sit® Oppo- 
sitifoli®. CorymbifersB, Jussieu. Essential 
character : calyx imbricate, cylindrical ; 
coiqllets of the ray three-parted ; down 
many rayed, simple ; receptacle chaffy. 
There is poly one species, viz. T. prp- 
cumbens. 
TRIENS, in antiquity, a copper money 
of the value of one-third of an as, which on 
.one side bore a Janus’s bead, and on the 
other a water-rat. 
TRIENTALIS, in botany, a genus of the 
Heptandria Monogynia class and order. 
Natural order of Rotaceae. Lysimachice, 
Jussieu. Essential character : calyx seven 
leaved ; corolla seven parted, equal, flat ; 
berry juiceless. There is but one species, 
viz. T. Europoea, chick weed winter green. 
TRIFOLIUM, in hotwy, trefoil, age-, 
nus of the Diadelphia Decandria class and 
order. Natural order of Papilionaceae or 
Leguminosse. Essential character; flowers 
in a head ; legume scarcely longer than the 
calyx ; nectary opening, deciduous. There 
are fifty-one species. T. officinale or meli- 
lot, has naked racemous pods, dispermous, 
vyrinkly, and acute, with an erect stalk. It 
grows in corn-fields, and by the way-sides, 
but is nut, common. The stalk is erect, firm, 
striated, branched, and two or three feet 
high ; the leaves ternate, smooth, obtusely 
oval, and serrated ; the flowers are small, 
yellow, pendulous, and grow in long close 
spikes at the tops of the branches ; the pod 
is very short, turgid, transversely wrinkled, 
pendulous, and contains either one pr two 
seeds. The plant has a very peculiar strong 
scent, and disagreeable, bitter, acrid taste, 
but such, however, as is not disagreeable to 
cattle. The flowers are sweet-scented. It 
communicates a loathsome flavour to wheat 
and other grain, so as to render it unfit 
for making bread. T. repens, white creep- 
ing' trefoil, or Piltch clover, has a creeping 
stalk, its flower gathered into an umbella| 
