268 BULLETIN OF THE 
day after the capture of the adult. It is seen in a little different plane 
from the preceding, but in such a way that the organs already mentioned 
can be easily distinguished. We have in this stage an addition of most 
important character, for at this time first appears the beginning of the 
polypite. The larva is shown in such a way that the embryo is twisted 
somewhat as compared with former stages, and the hydrophyllium has 
its proximal edge so turned into view as almost completely to cover the 
yolk. By this new position of the larva the conical end of the primitive 
cavity near the float is well shown, while the two buds which later form 
the serrated hydrophyllia are thrown to one side. The most devel- 
oped of these last-mentioned organs has a spatulate form, and shows the 
three layers, epiblast, middle layer, and hypoblast, as well as a cavity 
which occupies most of the interior of the organ. The other hydrophyl- 
lium is not as well formed, and is more highly colored. 
In addition to the buds which have been mentioned as already formed, 
we have represented in this stage a significant thickening (pyt.) at one 
pole of the two layers which surround the yolk of the egg. This pole 
is situated in a point at right angles to that where the bud which forms 
the float first appears. The elevation of these two layers takes the form 
of asimple bud comparable with other buds of the primitive larva, and 
ultimately forms the first or primitive polypite of the Agalma. The 
elevation of the primitive polypite is reddish yellow and ciliated, with 
the lower layer slightly separated from the cells of the yolk. Although 
the point at which the polypite in Agalma develops is very different 
from that at which the same organ of Crystallodes, as recorded by Heckel, 
arises, these differences are not too great to have a similar morphological 
interpretation. Like all organs or parts of the Agalma body, the poly- 
pite originates as a three-layered bud from the surface of the yolk. Like 
them also it separates from the yolk-cells, leaving a cavity between the 
hypoblast and vitelline cells. A part of those walls of the yolk which 
enclose the yolk-cells becomes the outer wall of the float ; another part 
is modified into new buds, which develop into tasters, hydrophyllia, and 
tentacles ; and still another part forms the walls of the first-formed po- 
lypite. Can we not consider that the yolk-sac in this case, as in Crystal- 
lodes, is not changed into the polypite, as in Physophora and some other 
genera? 
From Fig. 16, Pl. III., taken five days after the capture of the Agalma, 
we may obtain a somewhat better idea of the relationship between the 
buds which form the float, the serrated hydrophyllia, and the first-formed 
polypite. In the view of the larva as here seen, we are looking at the 
