POR 
tcm, a fpecles of oftracion ; but of the diodcn, 
belonging to the clafs of amphibia nantes, accord- 
ing to the Linnsean diftribution. It ufually mea- 
fures from twelve to twenty inches; the body is 
very thick, and covered with a whitifh coriaceous 
fldn, befet with ftrong fliarp thorns, each of which, 
at it's bafis, has two other fmaller ones buried 
under the (kin; the aperture of the mouth is 
large; the lips are rough and rugged; and tvv'o 
broad bones fupply the place of teeth, one fitu- 
ated in the upper jaw, the other in the lower, 
both being (lightly arched and prominent. The 
eyes are large; and the eye-lids are elevated, and 
armed with four thorns from one to three inches 
in length. The belly is white; and the back is 
brown, fpotted with black; as are alfo the fides. 
This fpecies is found near the Cape of Good 
Hope. 
PORCUS ACULEATUS. See Porcu- 
pine. 
PORCUS FLUVIATILIS. An appellation 
by which fome of the old Latin writers exprefs 
the fifh called alfo cornua, and aurata; in Englifli, 
the ruffe. 
PORCUS GUINTENSIS, the Guinea-pig. 
A fmall animal, refembling the common hog, 
which has been domefticated in this country. The 
colour is a reddilh tawny; the hair is fhort and 
(hining; but it has no bridles, except a few near 
the rump. 
PORPUS, OR PORPESSE. An Englilh ap- 
pellation indifcriminately, though improperly, ap- 
plied to two different fifhes, the phocsena and the 
dolphin. However, Artcdi, who has attentively 
colleiled the fynonima of authors, tells us, that 
this name ought to be confined to that fpecies of 
the dolphin, the charafters of which are, accord- 
ing to his fyftem, that the body is almoft of a co- 
nic form, and fubacute, and t!ie back broad. This 
fpecies is the Phoca^na of Ariftotle, the Turfio of 
Pliny and Rondeletius, and the Delphinus Pho- 
cxm of Linnaeus. 
This fifh is ranked among the cetaceous kind, 
and is the fmalleft of the tribe, feldom exceeding 
five feet in length; whereas the dolphin, with 
which it is commonly confounded, is frequently 
known to meafure twelve feet: the fnout alfo of 
the Porpus or Phocgena is much fmaller than that 
of the dolphin, which is another difcriminating 
mark. 
The Porpus has a roundifli body, gradually 
growing fmaller towards the tail; the nofe is long, 
pointed, and furniflied with ftrong mufcles, by 
means of which it turns up mud and fand, in 
fearch of fmall animals. The (kin is fmooth and 
thin; the back is of a dufl^y bluei(h colour, al- 
moft black in fome individuals; and from the 
middle of the fides downward, it becomes whit- 
iftj. There are no gills, nor any aperture in their 
Head ; but in the middle of the upper part of the 
head, before the brain, there is a pipe or fpiracle, 
of a femilunar form, through which the fifli re- 
fpires, and fpouts water : this pipe terminates out- 
wardly in one hole, but within is divided into n 
bony feptum, fo as to reprefent two noftrils ; and at 
it's lower end it again becomes one hole, opening 
into the mouth by a common orifice, furnifhed 
with a very ftrong fphindler mufcle, by means of 
which it is (hut and opened at pleafure. Above 
this fphinder, the fides of the pipes are lined with 
a glandulous fle(h, from certain fmall openings in 
^vKicI^, when prefTed, a glutinous liquor iffucs. 
POR 
Above the noftrils there is a ftrong valve of mem- 
brane, ferving to ftop the pipe at pleafure, and to 
prevent any water from gaining admiffion, except 
when the animal requires it. Within the fiftula 
there are fix blind holes, without any oudet; four 
tending towards the fnout; two placed above the 
valve which ftops the noftrils, and two beneath 
it : the other two tend towards the brain, having 
a long and narrow cavity, which feems intended 
for the purpofe of fmelling, though, on opening 
the brain, no fuch olfaflory nerves are difcover- 
able. The eyes are fmall ; the auditory duds, if 
any, are extremely minute; and the teeth, which 
are forty-eight in each jaw, are fmall. There are 
two fins on the breaft, and one on the back, which 
are cartilaginous and flexile ; the tail is flightly 
bifid, forming the figure of a crefcent in a hori- 
zontal pofition, like thofe of the cetaceous kinds ; 
not vertical, as in other fifties. Nature's inten- 
tion is, in this pofition of the tail, that it may 
fupply the place of the hinder pair of ventral fins 
in other fifli, thofe of the cetaceous kind having 
none fuch. Thefe fins (in other fifli) ferve to 
balance the body, and keep it under water, an- 
fwering in many refpeds the hinder legs of qua- 
drupeds and hence we m.ay obferve, that thofe 
fiflies which are not fuppliedwith this hinder pair 
of fins, nor the horizontal tail, cannot fufpend 
themfelves at eafe in the water, but are compelled 
to keep grovelling at the bottom: this is the cafe 
with eels, and other fimilar fifh; but the ufe of re- 
fpiration being as neceflluy to the Porpus as to 
quadrupeds, Nature has abundantly provided for 
thatdefedt in the hinder fins, by giving it atranf^ 
verfe tail, afftfted by which it can in a momenC 
throw itfelf on the furface from the deepeft water. 
The lungs and heart refemble thofe of quadru- 
peds. The brain is large, and formed like that 
of a man; and probably an obfervation of this 
particular has given rife to the opinion that thefe 
fifties pofl'efs a great fhare of will and underftand- 
ing. The tongue is flat, pectinated at the edges, 
and united to the bottom of the mouth. The 
blood of the Porpus is as warm as that of qua- 
drupeds; and the blubber, or fat, which lies in 
great quantities under the (kin, affords a vaft 
quantity of excellent oil. 
Theie fifhes are found in great numbers in all 
fuch parts of the fca as wafh the Briti(h iflands; 
but in ftill greater at thofe periods when fifh of 
pafTage make their appearance, which they purfue 
up the bays with the utmoft eagernefs. In fome 
places they almoft darken the fea as they rife above 
the water to refpire. However, they not only 
hunt their prey near the furface, but often defcend 
to the bottom in fearch of fand-eels and fea- 
worms, which they diflodge from the fand. 
To contemplate the various revolutions of 
fafhion in the fingle article of food only, would 
be curious and entertaining; we fiiould then find, 
that the fea-gull, the heron, and the fat Porpus, 
were once efteemed delicacies; the latter in par- 
ticular formed a royal difli, even fo late as the 
reign of Henry VIII. and, from it's magnitude, 
muft have cut a refpe6lable figure at table. In 
a houfhold book of that prince, extrafts from 
which appear in the third volume of the Arch- 
aelogia, it is ordered, that if a Porpus (hould 
prove too big for a horfe-load, allowance ihould 
be made to the purveyor. Even in the reign of 
Queen Elizabeth, this fifti continued in vogue ; 
for Dr. Caius, in mentioning a dolphin which was 
prefented 
