f ( 366 
PROCEEDINGS OF LEARNED 
) [May by 
SOCIETIES. 
ane 
ROYAL SOCIETY OF LONDON, 
R. Grirritus has, by the medium 
KN of Sir Jofeph Banks, laid betere the 
Royal Society, a ihe of a rare 
Species of Worm Shells, difcovered at 
Rattoo, an ifland north-weit of Sumatra. 
Thefe fhells were procured in a {mail 
{fheltered bay, with a muddy bottom, 
furrounded by coral reefs, It appears 
that the animal throws out tentacula 
from the two apertures of the apex 
of the fhell, that refemble the fmall 
adtinie adhering to the rocks about 
Padang, and that the body of the 
fhell is filled with a foft gelatinous 
fleih, fimilar to that of the teredo navalis. 
Mr. Griffiths did not obtain a fingle per- 
fect fhell, the longeft that came into his 
poffefiion was five feet four inches in 
Jength, and the circumference at the bafe 
nine | inches, tupering upwards, to two 
and a half inch es; the colour on the out- 
fide was milk-white, the inner furface ra- 
ther of a yellow tinge. This fpecimen was 
nearly perfect, haymg a fmall part of the 
lower extremity entire. In almoft all the 
fpecimens the fhells had adhering tothem, 
about a foot or more from the top, the 
fmall cockfcomb oyfter, fmall ferpule, 
&c. confequently they mutt have been at 
that diftance, protruded from the hard 
mud, in confequence of a violent earth- 
quake that. had Benue previoudly to 
the difcovery of the fhells. Thefe tube- 
fhells differ much among themfelves, not 
one of them being correfpondent in fize 
and thicknefs to another. The large end 
of the fhell is completely clofed, and has 
a‘rounded appearance ; at this part it is 
very thin, The finall end or apex is very 
brittle, and is divided by a longitudinal 
feptum running down eight or nine in- 
ches, forming it into two * diftinét tubes, 
melofed within the outer one, from 
whence the animal throws out tentacula ; 
the fubftance of the fhell 1s compofed 
of layers having a fibrous and radiated 
appearance, covered externally with a 
pure white cruft, and miternally is of a 
yellow tinge; the external furface is 
®equently interrupted in a tranfverfe di- 
reétion by a fudden increafe of thicknefs 
which probably indicates different ftages 
in the growth of the-fhell, although they 
are at unequal diftances, fometimes at 
fix inches, at others at four in the fame 
fhell. Thefe imterruptions bear a rude 
end uufinifhed appearance, and do not 
extend into the radiated fubitance, but are 
merely on the out-fide fhell which has 
rather a finooth furface, but imprefied 
with the irregularities of the fubfiance 
with which it was in contaét. It is the 
great length and fize of thefe theils 
which are the largeft of the teftacea of a 
tubular form yet difcovered, and the di- 
vilion of the upper part, which confiitute | 
their principal peculiarities, 
In a few weeks after the foregoing 
defeription was read, Mr. Home commu- 
nicated fome obfervations on the Shell 
of this Sea Worm, proving it to belong to 
a {pecies of the Teredo, with an account 
of the anatomy of the Teredo Navalis. 
By analyfis Mr. Harcuer found that the 
fhell was compofed of carbonate of lime, 
and an animal gelatinous fubftance, 
which is greater in quantity than in the 
chama gigas, but lefs than in the common 
oyfter. We cannot follow Mr. Home 
through all the minute anatomical de- 
feription that he has given,’ but felect 
fome of the more interefting obfervations. 
The heart ‘is fituated on the back of the 
animal; in the middle between the mouth 
and the lower end of the ftomach: the 
ftruciure is fuch that it admuts of only a 
fingle circulation, as in other animals 
which breathe through the medium of 
water, but the mode of its being perfor- 
med is different from that in fifhes; in 
the teredines the bleod paffes directly 
from the heart to the different parts of 
the body, and returns through the vetfels 
of the breathing organs to the heart, 
while in fithes it goes firft to the breathing 
organs, and then to the different parts of 
the body. This peculiar circulation be- 
comes alink in the gradation of the modes 
of expofing the blood to the air in diffe- 
rent animals, it appears to be lefs per- 
fect than in fithes, but is more perfect 
than in caterpulars. 
The mode in which the breathing-6r- 
gans of the teredines are fupplied with 
water, makes it evident that all fea- 
worms, as well as other foft animals, 
which have no cavity for the reception of 
fea-water, muit. have breathing-organs 
placed externally. This is the cafe with — 
all the wéinie inet with in the Weft In- 
dies, called animal flowers; and the 
beautiful membranous expanfions they 
difplay, refembling the petals of flowers, 
arein fact brea whing-organs, not tentacu- 
i for catching food. The teredo gigan- 
‘eo, when arrived at its full growth, clofes 
up ihe end of the fhell. Enis the teredo nas 
~ yalis 
