A S T E 
they are feen of their full length ; at other times, no part 
of them is feen but the extremity of each, which is torm- 
ed like a fort of button, or bead, being lomewhat larger 
than the red of the horn. 
The mod lingular of this genus is the caput Mcdufx y or 
Magellanic ftar-nfh, reprelented in Plate I. of afterias. It 
is called Medufa’s Head, becaufe it bears fome refemblance 
to the fnaky hair which painters have made peculiar to 
Medufa. The body is divided into five parts or rays, as 
may be feen in the upper figure of the plate, which re- 
prefents the belly or under part of the animal. In the cen¬ 
ter are obferved fome hollow rings, which, as it isfuppofed, 
conditute the month, fince they are furnilhed with pores, 
through which the creature receives its nouriihment in the 
water. To the under part of the five rays are affixed a 
great number of legs, difpofed in order, and by the help 
of thefe the animal contrives to walk, though indeed but 
very flowly. In the fpace. between is a black thick fkin, 
that covers the back or upper part of the body, which is 
divided by ribs, as dievvn in the lower figure; from the 
center of which grows out five double, or ten fingle, arms 
or rays, of a yellow or reddifh colour, and ranged two and 
two. The rays are fub-divided into two parts, and each 
of thefe into two other branches, which fucceffively be¬ 
come in proportion fmaller and more numerous, till the 
ray terminates in an infinite number of fmall ramifications. 
All the branches, beginning from the body, were, in the 
animal reprefented in this plate, about a foot and a half 
long, and the animal meafured upwards of three feet in 
diameter. The body, and all the rays, even to the extre¬ 
mity, are compofed of hard cartilaginous vertebrae, which 
refemble a ftar or di(k, and are furniffied with a prickle. 
It mud: be remarked that every ray ultimately dil'parts it- 
felf into 512 extremities, the five rays therefore all toge¬ 
ther are feparated into 2560. Now, every branch, having 
512 extremities, is compofed of 1023 joints; the five rays 
therefore confift of 5115. As every ray contains upon an 
average fix vertebrae, there are all together 81,840 cartila¬ 
ginous vertebrae ; when therefore one of thefe creatures 
comes to its full and perfect growth, the joints, extremi¬ 
ties, and vertebrae, multiplied together, produce a number 
almofi incapable of being counted! As the ancients rank¬ 
ed this creature among the vegetables, they were doubt- 
lefs of opinion that it drew its nouriihment through a num¬ 
ber of pores, fomewhat like flowers which grow in the 
water. But Llnnteus, and all the modern naturalifts, find 
its mouth very diftindtly in the centre, where five valves 
are united in a point. All the claws and joints are move- 
able, and lie extended in the water, which makes the ani¬ 
mal appear perfectly like a flower in full bloom. It is of¬ 
tentimes found upon a rock, or twilled round a coral. In 
order to take thefe fiffi, they touch them with a Hick, to 
which they immediately adhere. When drawn out of the 
water they hang down loofely like a bundle of flax, and 
when put down to be examined, they contradt themfelves 
and become hard. The fragments of thefe rays or claws 
furnilh the foflil entrochi. If we drown this animal in 
brandy or fpirits of wine, and keep the rays flat and ex¬ 
panded in the execution, it is eafy to extract, by means of 
a pair of forceps, the ftomach of the animal whole and en¬ 
tire through the mouth. With refpedt to the difference 
between the large and fmall fpecies, the one has the claws 
lefs divided, and the other all forked. This fpecies is 
found in the Indian ocean, and at the Cape of Good Hope. 
In the North Seas, and near Archangel, it is faid fome are 
found of a prodigious lize. The Cafpian fea, however, 
abounds with the larged fort of Medufa’s head. This 
creature feems to form the medium by which nature pafles 
from naked worms to tedaceous animals, and fliell-filh in 
general. 
Befides the caput Medufie, this genus comprehends ma- 
nv fpecies, which differ from eac*h other as much in their 
their liructure as in the number of rays. Some have 
them fmooth, others jagged, rough, prickly, or tuberous 
and furrowed The generality of thefe creatures are ob- 
, VoL.il. No, 72. 
R I A S. 301 
ferved to have five rays; but thofe having only four are 
as uncommon as thofe with above five. Some are called 
ftar-fifh, others fea-pies, others comets, and fome bear 
the name of fun-filh. In general they can fwim witheafe, 
and they are alfo able to adhere firmly to rocks, or the 
bottom of the lea. The following fpecies arc found on the 
Britifli coad : 1. The glacialis, with five rays, dcprelfed, 
broad at the bale, yellow, and having a round driated oper¬ 
culum on the back, is the mod common; it feeds on oif- 
ters, and is very deltrudtive to the beds. 2. The clathatra, 
or cancellated fea-fiar, with five lhort thick rays, hirfute 
beneath, cancellated above, is found with the former, but 
more rare. 3. The oculata, with five fmooth rays, dotted 
or puiidtured, is of,a fine purple colour, and is found about 
Anglefea. 4. The hifpida, with five rays, broad, angula- 
ted at top, and rough with lhort bridles, is of a brown co¬ 
lour, and likewife found about Anglefea. 5. The placen¬ 
ta, with five very broad and membranaceous rays, ex¬ 
tremely thin and flat, is found about Weymouth. 6. The 
fpherulata, with a pentagonal indented body ; a fmall glo¬ 
bular bead between the bale of each ray ; the rays deader, 
jointed, taper, and hirfute on the fides; found off Anglefea. 
7. Tire decacnemos, has ten very (lender rays, with num¬ 
bers of long beards on the fides; the body is fmall, and 
furrounded beneath with ten fmall filiform rays. It inha¬ 
bits the wedern coafls of Scotland. 
There arc feveral foreign fpecies very curious, the prin¬ 
cipal of which are as follow : 1. Afteria reticulata, or re¬ 
ticular dar-fifli, with five rays; in which the whole fub- 
ftance is compofed of mufcular and cartilaginous excre- 
fcences ; the fmall bones, which are found in the interior 
part of every ray, and which fpread themfelves through 
it, are of an oblong figure, and have a large furface up¬ 
wards like a blade-bone ; and, being placed one after the 
other, reprefent a fort of net-work. The other bones are 
fmall fpherical fubfiances, of unequal furfaces, which have 
on the outlide the figure of a nipple, from which projects 
an apophylis or cartilaginous protuberance. But, when 
thefe bones have attained their full lize, they are in the 
fliape of a dar, like thole toward the centre part of the 
animal. The number of thefe may perhaps amount to 
fome thoufands. They are all united together in a tough 
fubdance refembling fhagreen, and feem on theoutfide to 
be an alfemblage of fmall points or grains, like millet or 
poppy feed, which probably encreafe by degrees, and con¬ 
ditute the growth of this creature. The interior part of 
them is a mucilage, compofed of veficles placed under the 
bones, which feem to alfilt the motion of the apophyfes, 
as they expand and contract themfelves alternately. M. 
le Kade, having anatomifed an ajleria rubens of Linnaeus, 
has deferibed the interior parts of the dar-fi(h with great 
accuracy. In the centre of the inferior furface is difeo- 
vered an opening, which divides itfelf into five furrows, 
extending to the extremity of each ray. At this aperture 
is obferved a great number of points, and each fide of the 
furrows is furniflied with the fame, every one of which is 
fupported by a.fmall velicle on the fide of the furrow, 
which perfectly refembles a hand with five fingers. By 
the help of thefe points or nipples, which amount from 
five hundred to a thoufand, the filh appears to advance 
along the bottom of the fea, though indeed exceedingly 
flow, and almofi: imperceptible. The mechanifm of this 
motion conlifts in the veficles, which are placed under thefe 
points or legs, being filled with a clear liquid, by the pref- 
fure of which the legs are forced out; and they again con- 
trad! themfelves as loon as the liquor runs back, like the 
horns of a fnail. In the water the motion becomes more- 
nimble, probably becaufe in a fluid the refinance is not lo 
great. The five fides in general form a regular pentagon ; 
but, when the animal is drawn out of the water, it is with 
great difficulty the rays are'kept from being disfigured, 
and put out of their place. It often happens, by lbme ac¬ 
cident, that a ray is torn from the body ; in which cafe 
the animal is endued with the power of reproduction, lince 
another lhortly grows out and fupplies its place. .The 
4 H ’• natural 
