Phew tas OUR wor. LNgs & @4T. S, 
for a more proper opportunity. But I hall 
now briefly relate what appearedat firft fight to 
me on the inner and outfide of this Mufcle, and 
in its fhell, and fhall, in particular, explain 
fome things concerning the infertion of its muf- 
cles ; whereby the hiftory of what I have be- 
fore faid of the Mufcles being inferted in the 
fhells of the Snails, will be confiderably illuf- 
trated. 
When the fhell of this little Mutfcle is care- 
filly broke in little pieces with a forceps; and 
feparated in the part where the Mufcles are 
inferted, then offers itfelf to view in the crea- 
ture, its lips, and with this the verge; thefe 
wind about the whole body, and cover it as it 
were with two wings or lips, One of thefe is 
obferved to be, Tab. X. fig. vi. aa, bent back 
to the fide of the body. On the lower fide of 
it, and likewife on the other fide of the body, 
are feen papille as before mentioned 4 4, tinged 
with a black colour, which may eafily be wiped 
_ off with a brufh. The papilla feem to me to 
be the extremities of fo many tubes or trunks, 
whereby the Mufcle draws into its body, {mall 
particles of mud and flime, for the gullet feems 
to communicate with them. On each fide of 
the body are four branchiz or gills, each con- 
fitting of three membranes, the middle where- 
of is formed like a bull-rufh mat, and is com- 
pofed of longitudinal and tran{verfe filaments, 
and may be feen through both the external 
membranes. All thefe filaments feem to me 
to be tubes, through which the blood moves as 
it does in fifh, The largeft veffels are fituated 
in the lower part of the mufcle; and from 
thence arife, I think, thofe tubes, which, who- 
ever purfues them fo far, will find pretty ftrongly 
connected with the papilla that draw in the 
food. On each fide, the Mufcle Tab.X. fig. 
vi. cccc has four fuch larger branchiz or gills, 
and four other fmaller ones, dd dd, placed to- 
wards the hinder part. 
The body itfelf confifts of two parts, a 
hard e and foftf ThefeI take to be the thorax 
and abdomen. ‘The harder part is made up of 
a congeries of many mutcles, which run from 
one fide of the body to the other, with ftrata 
or layers of long fibres, and being then carried 
over the foft part towards the branchiz or gills, 
and wings or lips, they afterwards give various 
mufcles underneath to the belly. The thorax 
rifes into a point, and is of a colour fomewhat 
approaching to yellow. _When opened it ex- 
hibits many mufcular fibres running tranfverfely 
from one fide to the other, from which the 
thorax obtains its hardnefs and ftrength. Un- 
der this is placed the brain covered, with a 
bright-yellow membrane; but the fpinal mar- 
row and nerves are white, and they are divided 
into branches which are detached in great num- 
bers to the mufcles, 
I find four different parts in the abdomen, 
a liver, fat, an afhy-gray fubftance, and feveral 
membranous and mufcular expanfions. The 
part which I take to be the liver, is very large; 
it confifts of a congeries cf {mall oblong glan- 
larger fhell-fith of this kind. 
5 
dules, which are placed near the hepatic veflels, 
and refemble fo many uvule refting on their 
little fupports. Its colour is a blueifh red, and 
where the veffel is thickeft, a glutinous matter 
is contained in it. ‘There is a great quantity of 
what I call fat in the abdomen; it is divided 
into {mall glandulous little knots, and is of a 
bright white ‘colour, fo that one would take 
thern for little eggs, only there is fo great a 
quantity here, that it reaches even to the fpinal 
marrow. Many, membranous and mutcular 
expanfions are likewife feen in the belly, but 
whether they are interwoven with veflels and 
nerves, or with mufcular fibres, I cannot exactly 
determine. To conclude, there is likewife a 
great quantity of afh-coloured matter, diftri- 
buted among the fat: we find the fame fub- 
ftance depofited round the larger vefiels of the 
branchiz or gills, and in many other places. 
I could not hitherto difcover either a heart 
or a ftomach in this creature, but fhall referve 
both for further inquiries. The principal muf- 
cles that arife from the back are here very 
ftrong, and divided into many tendinous fibres, 
and are firmly inferted in the {kin or ftony fhell 
of the creature, fo that by this means various 
holes and cavities are obferved to be formed in 
the fhell, becaufe fome of the tendons are fixed | 
in it deeper than in others. Out of the back 
arifes, among others, a very beautiful {mall 
miufcle, which pafles through the fhelly part 
that joins the two valves of the thell together, 
as through a pully, and is afterwards inferted 
in the fharp-pointed extremity of the fhell: but 
the mufcles are not fo ftrong about the acute. 
extrernity as elfewhere. The fame ate like- 
wife very fhort, which is the réafon that this 
Mufcle can open the valves of its thell but a 
little way; fo that if you attempt to ftretch 
them further, even with the leaft force, they 
immediately break. 
On the infide of the fhell are obferved five 
particular parts, in which the mutcles of this 
creature are inferted, that is in the fore part of 
the acute extremity, where the infertion is in- 
deed broad and formed into a circle, Tab. X. 
fig. vil. a, but not very ftrong. The Mutfcle 
is very {trong at the thick end of the fhell, be- 
caufe the mufcles are there very firmly united 
with the ftony bone: but one may there fee 
four little apertures 4 funk in the fhell, wherein 
the tendons of the mufcles are united with the 
fhell, or rather change into a fhelly fubftance. 
The mufcles of the lips are inferted, but not 
ftrongly, almoft in the whole circumference of 
the fhell next to its extremity ccc. We obferve 
that the fpiral worm d of this thell {wells fome- 
what beyond its arched cavity. There arealfo 
two eminences ee, by the help of which both 
valves of the Mufcle are very ftrongly joined 
together as by ginglymus; which, together 
with the parts wherein the mufcles are inferted, 
make a very beautiful appearance in fome other 
{pecies of Mufcles, and are wonderful in the 
This thell is on 
the infide like that of mother-of-pearl, Qn the 
Z qutfide 
