O N C 
fcribed in the fifth volume of the Linnasan Tranfa&ions, 
1798. It inhabits Bengal, on the leaves of the Typha ele- 
phantina of Roxburgh. In appearance it very much re- 
fembles a Umax, orihail; but differs principally in want¬ 
ing the fhield and lateral pore, and in being furnifhed 
tvith a vent behind. 
The body, in its ftate of reft, is oblong, convex above, 
about an inch long, and three quarters of an inch broad ; 
but, when the animal creeps, it becomes linear, obtufe 
at both ends, about an inch and a half or two inches long, 
and half or three quarters of an.inch broad ; and the arms 
and feelers then become vilible. It is flat, black, and 
fmooth, below ; above, convex, afh-coloured, and covered 
with glandular tubercles, irregular,in fize and petition : 
from thefe tubercles the name (Onchidium) is derived. 
United lengthwife, on the under fide, to the body, is what 
Linnaeus would call the foot of the animal, as being the 
organ of motion and liability. It is of a dirty-yellow co¬ 
lour, linear, about a quarter of an inch fhorter than the 
body at each end when in motion, and obtufe at the ends: 
it is flat below, and perpendicular at the fides. It coniifts 
of many tranfverfe rings, like a Lumbricus, or earth-worm, 
by means of which the animal can move with tolerable 
quicknefs, adheres firmly to the fmootheft furfaces in all 
directions, and turns itfelf flowly round. The head is 
yellowifh, fmall, and placed under the fore part of the 
body, at the fore end of the foot, to which it is joined. 
During the various operations performed by the animal, 
its head is conffantly changing its form and fize ; and, 
when entirely at reft, it is drawn up fo as to be hardly per¬ 
ceptible. When fully expanded, the head is flat and 
oval below ; and there is a mouth placed lengthwife 
with refpeft to the animal. This mouth alfois conffantly 
varying its fhape from circular to linear. From each fide 
of the head comes what Linnaeus calls an arm (braehium), 
like thofe of the Scyllaea, conffantly varying its form and 
fixe, and at times entirely drawn in. Thefe arms arefolid, 
comprefi'ed, and, when fully expanded, fomewhat palma- 
ted ; at leaft they are much broader and flatter towards 
the outer extremity. From the forehead arife two feelers, 
exaftly like the horns of a lhail, and having the appear¬ 
ance of eyes at their extremities. This is not, like many 
of the worm kind, an hermaphrodite animal ; for the male 
and female organs of generation are in diftin< 5 l individuals; 
but nothing is known with regard to the geftation of 
the female, or how ihe produces her young. On the an¬ 
nexed Plate, fig. 1 reprefents'the fpecies of the full fize; 
fig. 2, the fame lying on its back ; fig. 3, a fide view of the 
head. 
2. Onchidium Peronii. Native of the Ifle of France, 
and defcribed in Cuvier’s Memoirs on the Anatomy of 
the Mollufca, 1817. The difleftion of this fpecies re¬ 
veals an extraordinary phyfical fad ; namely, the pre¬ 
fence ofthree ffiftind livers, with their refpedive fyftems 
of velfels, and differing only in fize and pofition. It is 
alfo worthy of remark, that, in this newly-difcovered fpe¬ 
cies, an hepatic liquor performs the fundions of thegaf- 
tric juice. Peron brought from Timor, one of the Mo¬ 
lucca iflands, an individual exactly correfponding with 
the preceding, except that it was rather fmaller ; and the 
author received a much more minute fpecimen, not ex¬ 
ceeding eight or ten lines in length, from the coaft of 
Brittany. 
The Limax nudus cinereus terreftris, of Sloane, is faid 
likewife to belong to the prefent genus. 
ONCID'IUM, f. in botany, a genus of plants, infti- 
tuted by Swartz, and conlifting chiefly of fome fpecies 
of Epidendrum, as the altiflimum, ceboletta, &c. which 
vary in fome degree from the generic character. Thefe 
variations are not fo conflderable as to make it necelfary 
for us to repeat the defcriptions of thofe fpecies. See 
Epidendrum, voh vi. 
ONCI'NO, a town of Italy, on the Po: fourteen miles 
weft of Saluzzo. 
ONCOBA,/. [fo called by Forlkal from its Arabian 
Vot. XVII. No. 1192. 
ONE 485 
name or,cob.) In botany, a genus of the clafs polyandria, 
order monogynia, natural ord£r tiliacete, Juff. Ge¬ 
neric characters—Calyx : perianthium inferior, of one 
leaf, permanent, divided into four deep, concave, obtufe, 
legmen ts. Corolla: petals eleven or twelve, lpreading, 
toothed ; the outer ones longer than the calyx ; the inner 
fmaller,unequal. Stamina: filaments, numerous, thread- 
fliaped, eredi, inferted into the calyx ; antherae ereft. 
Ample, linear. Piftillum : germen fuperior, globofe, lon¬ 
gitudinally furrowed ; ftyle cylindrical, longer and thick¬ 
er than the filaments 5 ftigma orbicular, furrowed, feVen- 
lobed. Pericarpium : berry globular, pulpy, of one cell, 
and many oblong comprefied feeds.— Effential CharaBer . 
Calyx of one leaf; petals numerous; berry oi one-cell, 
many-feeded. 
Oncoba fpinofa, the only fpecies. It is a native of 
Egypt and Senegal, where it is called, according to Adan- 
fon’s Herbarium, dimb, or rimbot. This is rather a lofty 
tree, with alternate warty branches, each furniffied with 
one or two fpines about two inches long. Leaves alter¬ 
nate, fhortly ftaiked, ovate, pointed, ferrated, fmooth. 
Flowers folitary, large, white; calyx white internally. 
The berries are faid by Forlkal to be eaten by' children. 
This genus is adopted by Gmelin, but omitted by Miller 
and Martyn. 
ON'DA, a town of Spain, in Valencia: twelve miles eaft 
of Segorbe. 
ON'DA, or St. Vincent de la Pazes, a town of 
South America, in the province of St. Martha: fifteen 
miles eaft of Los Reyes. 
ONDARRO'A, a town of Spain, in Bifcay: eight 
miles weft of St. Sebaftian. 
ONDE'E, adj. [French.] Wavy ; a term in heraldry. 
ONDE'GA, a town of Abyflinia : fifty miles fouth- 
weft of Tfelga. 
ON'DER BOK'KEVELD, a territory of Southern 
Africa, being one of the tranfmontane divifions of Stel- 
lenbofch, near the Cape of Good Hope. This is the ele¬ 
vated flat furface of a table-mountain, whole fides on 
the weft and north are high and almoft perpendicular 
rocks, piled on each other in horizontal ftrata like thofe 
of Table-mountain at the Cape ; but it defcends with a 
gentle flope to the eaft ward, and terminates in Karroo- 
plains. The grades on the fummit are fliort, but fweet; 
and the fmall Ihrubby plants are excellent food for lheep 
and goats. The horfes are among the belt which the co¬ 
lony produces; and the cattle thrive well. In. fome of 
the valleys, where the grounds admit of vegetation, the 
common returns of wheat are forty, and of barley fixty, 
for one, without any reft for twenty years, without fal¬ 
lowing, and without manure. The foil is deeply' tinged 
with iron, and abounds with mafles ofiron-ftone. Barrow s 
'Travels in Southern Africa , vol. ii. 
ON'E, adj. [an, ten, Sax. een, Dutch; ein, Germ, vi, 
Gr.] Lefs than two; Angle; denoted by an unit.—Pin- 
darus the poet, and one of the wifeft, acknowledged alfo 
one. God the moll High, to be the father and creator of all 
things. Ralegh. 
Love him by parts in all your numerous race, 
And from thofe parts form one collected grace; 
Then, when you have refin’d to that degree. 
Imagine all in one, and think that one is he. Dnjdcn. 
Indefinitely: any; fome one: 
Took pains tomake theefpeak, taught thee each hour 
One thing or other. Shah ejp care's Tempejl. 
It is added to any .—When any one heareth the word of 
the kingdom, and underftandeth it not, then cometh the 
wicked one, and catcheth away that which was fown in 
his heart. Mattli. xiii. 19.—If any one ^prince made a 
felicity in this life, and left fair fame after death, without 
the love of his fubjedts, there were fome colour to defpife 
it. Suckling. —Different; diverfe ; oppofed to another .— 
It is one thing to draw outlines true, the features like, 
6 H the 
