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Transactions of the 
containing the two Genera Stephanoceros and Floscularia ; and 
Melicertad.e, containing the two Genera Melicerta and Lacinu- 
laria : and to see at a glance where the first Family differs from 
the second, and where the Genera of each agree in their general 
organization, the diagrams (Plate XXIII., Figs. 1, 2, 3) are sub- 
mitted, on each of which a line is drawn from the mouth to the anus ; 
and if we consider this to be the axis of the body, we find in the 
first Family that both the marginal wreath of setae, the trochus 
(which I employ also for the ciliated wreath of the second), and the 
secondary belt of cilia, the cingulum, surround the axis, and the 
anus is placed on the neural side, the side on which the ganglion is 
seated; hut in the second Family the trochus subtends the axis, 
and the cingulum, after traversing the margin of the corona (the 
miscalled dish), also surrounds the axis, while the anus is situated on 
the opposite, the hsemal side. The trochus is indicated on the 
figures by a full black line, and the cingulum by double fine lines. 
There is a particular reason for rejecting such inconsistent terms 
as dorsal and ventral in this SECTION, for in the Family Flos- 
cularle they virtually represent the same side of the animal. I 
shall therefore, with the examples of both Huxley and Allman 
before me, employ hsemal and neural, on the same grounds that 
Allman adopts them in his ‘ Memoir of the Fresh-water Polyzoa,’ 
viz. that “notwithstanding an apparent contradiction in denomi- 
nating as £ haemal ’ any portion of an animal totally deprived of a 
blood-vascular system, they have the advantage of stating a simple 
fact.” 
The organization of these two Families differs conspicuously in 
their physique, and equally so in their Dermal and Alimentary 
Systems ; and in selecting an individual from each, for the purpose 
of eliminating their true relations, I shall employ Floscularia cam- 
panulata to illustrate the one, and Melicerta pilula the other, from 
the fact that they have recently been recorded as 1 New Species of 
Rotatoria ’ by Dr. F. Collins ; * this last species being a Form with 
which I have for some years been intimately acquainted, which I 
had denominated Melicerta pilula (long before I committed my ob- 
servations to print), from the fact that she fortifies the gelatinous 
basis of the theca with her own excremental pilules. This, as a 
new species, was recorded in a paper communicated to the Quekett 
Club in the year 1868 by Mr. J. G. Tatem, who at that date ad- 
mitted that he had no specific title wherewith to denominate it. 
And Dr. Collins, in describing this, states that “ the pellet with 
which the animal builds its tube is formed in a hind of sac situated 
at the lower extremity of the abdomen, and is discharged through 
the cloaca.” He describes also a new species of Floscularia, which 
he denominates Floscularia trilobata , somewhat similar in appear- 
* ‘ Science Gossip,’ January, 1872. 
