234 DENTALIAD &. 
renders the discrimination of organs of this character a matter 
of some difficulty. Ihave not discovered any exserted organs 
of reproduction, and I think from various considerations that 
this animal is an hermaphrodite, but without congression. 
Under the microscope, in the midst of the general mass, 
several small egg-shaped globules, having at one of the axes a 
minute, apparently tubular filament filled with a glairy fluid, 
may be seen in some individuals, but not in all, as I have 
sometimes searched in vain for them; these may be the virile 
fecundating organs, which are perhaps only apparent at certain 
stages of gestation. 
I have extended these observations to an unusual and 
almost inconvenient length: the carious and anomalous 
structure of this mollusc, and the multitude of interesting 
characters attached to it, exhibit such modifications of the 
organs of the typical Gasteropoda as appear to give it a claim 
to be considered as the point of transition from the Bivalve 
Mollusca to the great change in figure and faculties which 
nature has produced in the superior developments of the 
Gasteropoda ; and perhaps, from a review of this account of 
these organs, malacologists may be induced to think that it 
will appropriately form one of the first, if not the first link, m 
the chain of the Gasteropoda. The symmetrical subventral 
position of the branchiz, the posterior flow of water to them, 
and the resemblance of the foot to that of some of the 
Bivalves, combined with the similar character of its action, 
appear in a striking manner to show its connection with the 
Conchifera ; whilst by its cesophageal cerebral ganglions and 
completeness of the circulation, it has established its claims as 
a Gasteropod. There are also traces of alliance with some of 
the inferior classes: the red blood and vermiform configura- 
tion of the posterior part of the animal show some of the 
characters of the Annelides; but though we acknowledge 
these sources of its origm, we cannot fail to see how clearly 
the animal of Dentalium displays at various points the progress 
of advancement, and the ameliorations nature has so bene- 
ficently effected in its animality. 
