404 
I S I 
I'SIS, a name frequently given to the river Thames, 
before it joins the Thame at Dorchefter: but molt pro- 
babiy_without foundation. This river is only a branch 
of the Thames, which rifes near Minchinhampton in 
Gloucefterlhire, and joins the main ftream near Leehdale. 
I'SIS,/ Jointed Coral; in helminthology, a genus 
belonging to the order of zoopliyta. The generic cha- 
rafters are—Animal growing in the form of a plant; (fern 
ftony, jointed, the joints longitudinally ftriate, united by 
fpongy or horny junctures, and covered by a foft porous 
cellular flefh or bark ; full of little mouths, from whence 
the polypes with their claws come forth, through whom 
the eggs are produced. 
" This genus of zoophytes is very nearly allied to the 
Gorgonias, having a hard part within, which is the flip- 
port or bone of the animal, and a fofter part without, 
■which is its flefh. This foft part is furnifhed with organs 
that ferve both for nutrition and generation. Thefe are 
its polype-like fuckers, which are contained in, and ex¬ 
tend themfelves from, its cells, when in fearch of food. 
The difference between Ifis and Gorgonia is this, that the 
bony part of the Ifis is jointed, which is not fo in the Gor¬ 
gonia. Thefe joints are an admirable contrivance of na¬ 
ture, to fecure the'brittle branches of thefe animals from 
being torn to pieces. Without this, they could not 
arrive at the height of which fome. of them are found, 
viz. of two or three feet; for, by bending freely to and 
fro with thefe foft joints, they eafily refill the violent mo¬ 
tions of the fea. When the animals grow old, their Items 
have no more joints, that part being then ftrong enough 
to withftand the force of the waves. The foft genicu- 
lations then are only found in the (tenderer parts of the 
branches. 
1. Ifis ochracea, the Eaft-Indian coral: ftem ftony, ir¬ 
regularly channelled, as if eaten into; branches many, 
dichotomous, and fpread out; the joints connected by 
deep-yellow fpongy knobs. The flefh is of a pale yellow, 
full of ftarry mouths, that cover polypes with eight claws. 
This beautiful ifis is found in the Eaft-Indian Ocean, 
among the Spice-iflands. It is fo very liable to fall to 
pieces when dry, that good fpecimens of it are very rare. 
There is likewife a variety of it, whofe ftony part and 
flefh are quite white ; but the fpungy geniculations are of 
a brownifh yellow. This is the fubjett of Plate I. 
2. Ifis dichotoma, the dichotomous ifis: Item coralline, 
with fmooth joints and decorticated junctures. About 
half a foot high, fomewhat flexuous: joints clear flefh- 
eolour, with a cinnabar flefh befet with convex papilla:. 
Inhabits the Indian and Ethiopic feas. 
3. Ifis entrocha, the entrochous coral : item teftaceous, 
round, with orbicular perforated joints and verticillate 
dichotomous branches.. Stem about the thicknefs of a 
finger, with crowded flat orbicular joints perforated in 
the centre; the perforation pentangular, with the difk 
fubftriate from the centre. Outer bark, or flefh, unequal, 
and furrounded by a row of tubercles: branches thin, 
dichotomous, continued and not jointed. It fhould feem 
therefore that thofe foffile bodies called eutrochi arc petri¬ 
fied fpecimens of this fpecies of coral. Inhabits the 
Ocean. 
4. Ifis afteria, the ftar-coral: ftem teftaceous, jointed, 
pentagonal: branches verticillate, with a terminal dicho¬ 
tomous liar. Inhabits the Ocean, and is found foffile in 
all parts of Europe, and known by the name of the ftar- 
. ftone. 
5. Ifis hippuris, the black coral of India: ftem jointed, 
ftony, rifes into many loofe branches; the bone or fup- 
pott of the animal cenfifts of white, cylindrical, ftony, 
channelled, joints, connected together by black contracted 
horny intermediate ones. The flefh is whitifh, plump, 
and full of minute veflels; the furface of it is full of the 
little mouths of the cells, which are difpofed in a quin¬ 
cunx order, covering the polypes with eight claws. There 
are many varieties of this muchmdmired ifis. Some are 
dw arfilh, not above fix inches high; others, from a foot 
I S L 
to two feet and more. In fome, the ftony joints are 
longer, and the black horny joints very fhort; in others, 
the black horny ones are longer, but always more cors- 
t rafted. This' coral fpreads its bafe on rocks, by various 
turnings and windings, both of its bony and ffefhy part ; 
and, as it rifes, we find it inclofing fhelisand other extra¬ 
neous fubftances, that ftick to it, like the Gorgonias. 
This beautiful coral is often brought by our Eaft-India 
fhips from Prince’s Ifland, in the Straits of Sunda, on the 
fouthern coaft of Sumatra. Specimens with the flefh on 
them are rarely to be met with, as the Tailors generally 
ferape off the flefh to fliovv the beauty of the black and 
white joints. This is reprefented on Plate IT. 
6. Ifis coccinea, the dwarf fcarlet ifis: ftem jointed, 
flender, very red, and a little ftriated; joints united by 
fhort, fpongy yellowifli geniculations; flefh on the infide 
of a pale role-colour; on the outfide covered with little 
riling wart-like fcarlet cells, each furnifhed with.a mouth. 
This differs from tli£ dichotomous ifis of the Cape, in 
being much fmaller, and irregular in its branches. No¬ 
thing can exceed the brightnefs of its fcarlet colour. It 
is about two or three inches high, and was collefted on 
the coaft of Mauritius in the year. 1767, and prefented to 
Dr. J. Fothergill, with many other rare fea-produftions., 
by the furgeon of an Eaft-India .(hip. This beautiful 
fpecimen of the true red coral is fhown on the Helmin¬ 
thology Plate V. fig. 4. vol.ix See that article, p.357. 
alfo Coral and Coral Rocks, vol. v. p. 187-189. and 
the article Zoophyta. 
PSIT, a town of Ruffia, in the government of Irkutfk, 
on the Lena. Lat.6i.N- Ion. 123. 50. E. 
ISKARSKOIGORODf, a town of Ruffia, in the go¬ 
vernment of Tobolfk : 320 miles fouth-weft of O'odorfkoi. 
Lat. 60. 5. N. Ion. 59. 14. E. 
ISKASXAG'AMAGTS, a lake of Canada, eighty- 
four miles north-weft of Quebec. Lat. 47. 50. N. Ion. 72. 
25. W. 
IS’KER, a river of Wales, which runs into the Ufk 
two miles weft of Brecknock. 
IS'KIB, or Eskelib, a town of Afiatic Turkey, in the 
government of Sivas: twelve miles weft of Tlchurum, and 
thirty eaft-fouth-eaft of Kiangari. 
IS'KIM, a river of Perfia, which runs into the Arabian 
Sea in lat. 25. 45. N. Jon. 57. 9. E. 
IS'KOLDZ, a town of Lithuania, in the palatinate of 
of Novogrodeck: thirty miles fouth-ealt of Novogrodeck. 
ISKOROSC', a town of Poland, in Volhynia: forty- 
eight miles north of Zytomiers. 
I'SLA (Jofeph Francis de), a Spanlfh Jefuit of Madrid, 
who, after the deftruftion of his .order, retired to Italy, 
and died at Bologna in 1781. He was the author of a 
very celebrated work, entitled Hiftoria del Fra Geruridio 
de Campazas alias Zotes, Madrid, tome i. 1758, 8vo. of 
which an Englifh tranflation appeared at London, in 1772, 
in 2 vols. 121110. It is a bitter fatire on the ignorance of 
the monks; and, in a country where defpotifim and fu- 
perftition prevail, could not efcape perfecution. Scarcely 
had the firft part appeared, when an alarm was founded 
by the clergy at court,'fupported by fome of the bifliops; 
and the lupreme council of Caftile, to allay the ferment, 
was obliged to fupprefs the work, and to forbid the pub¬ 
lication of the fecond part. This romance, therefore, has 
become exceedingly fcarce, even in Spain; and it might 
perhaps ha.ve remained unknown in this country, had not 
d’lfia caufed the fecond part of the manufeript to be 
tranflated by means of the late Mr. Cumberland. It 
has alfo been tranflated into German, from the Englifh 
edition, vrith notes and illuftrations where necefl'afy. 
Since the time of Cervantes, no Spanifh writer has dif- 
played fo much wit and cauftic humour. Father dTfla 
pahlifixed this work under the feigned name of Francis 
Lobon de Salazar. Hirfelling's Manual of eminent Perfons who 
died in the eighteenth Century. 
I'SI.A, a river of Scotland, which rifes in Angusfhire, 
and runs into the Tay ten miles north of Perth. 
I'SLA, 
