Mr. W. Clark on the Animal of Dentalium Tarentinum. 329 
terior, observes that it is the only molluscum that has it so situ- 
ated ; but this anomaly, if it be so, I think I have disposed of. 
Those organs which I consider to be the symmetrical branchiz 
are termed by M. Deshayes the lobes of the liver, each pouring 
into the stomach the bile by their biliary vessels. I cannot per- 
suade myself that this view is correct ; I have submitted them to 
the microscope, and in each principal strand I have seen the 
leading vein distended with red blood as well as in the net-like 
connecting ramifications ; | therefore consider what are called 
the biliary vessels to be the branchial veins conveying the blood 
to the heart instead of bile into the base of the stomach. M. Des- 
hayes in his figure has omitted to mark the vein which runs at 
the dichotomous points of his organ, which, when viewed under 
high powers, is very visible, and which I take to be the branchial 
vein. 
What I term the salivary glands, are the branchiz with M. 
Deshayes, combining the functions of tentacula: he does not 
mention such glands. I must consider this assumption incorrect ; 
and to support this opinion I state that the heart is separated 
the whole length of the stomach from the bases of what M. 
Deshayes terms the branchiz : this is a position without parallel, 
as that organ is invariably in the closest contact with one end 
of the br anchize. That naturalist certainly connects the two organs 
by stating, as I think erroneously, that the heart sends great 
and numerous vessels to the branchie. Now the heart never 
transmits blood directly to the branchiz, but impels it into the 
system by arteries and ves, from whence, as I have already 
stated, it reverts to those organs. 
The filaments in dispute I have submitted to microscopical 
observation ; they only present the appearance of a complicated 
mass without a trace of particular arterial and branchial vessels, 
and they have nothing lke the symmetry of branchie ; I believe 
them to be merely secreting glands, and may perhaps combine 
tentacular functions. 
M. Deshayes is, I think, in error in stating that the aliment 
undergoes a second mastication: this idea has arisen from his 
having divided the gizzard into two parts, one of which he de- 
scribes as “ machoires,” and the other as an “ appareil dentaire 
assez compliqués ;” the fact 1s, there are no hard parts in the buc- 
cal pouch, which, when removed, there being no internal ceso- 
phagus, exposes to view the anterior part of the gizzard, which 
is likened to two spherical black pomts gaping like a small 
bivalve : these are only part and parcel of a whole—the gizzard, 
which may almost be called the stomach itself, as it fills the en- 
tire stomachal membrane, with the exception of the convoluted 
intestine at its base, consequently the aliment has no other mas- 
tication but of one denticular apparatus. 
