bulbs, both somewhat unsymmetrical. Textfig. 6 is a longitudinal 
section of a little older gonophore; the subumbrella cavity has been 
formed, but there is no trace of the manubrium; the velar plate 
is seen deeply sunk between the two tentacular bulbs. In this 
stage of development (as demonstrated by the other sections be- 
longing to the same series) there are, indeed, four radial canals 
separated from each other in the interradii, but the two, which 
Fig.4. — Gonophore at a very early stage of development, showing the first trace of 
a centi*al lumen. 
Fig. 5. External view of a young gonophore, with two large, unsymmetrical tenta¬ 
cular bulbs (f.). 
Fig. 6. Longitudinal section of a young gonophore. — t. tentacular bulb ; v. velar 
plate ; b. c. bell cavity; r. c. radial canal; per. periscarc; eet. ectoderm; 
end. endoderm. — For further description see the text, p. 7. 
are not hit in the section figured, do not reach beyond the level 
of the velar plate. — When the manubrium is developed, it is 
from its very first beginning radially connected with the canals, 
forming the mesenteries mentioned above. Textfig. 3 shows a cross- 
section of a fairly young gonophore with the radial canals still very 
wide; we see, how the subumbrella cavity at the level of the 
section is divided into four separated parts. 
The third tentacular bulb is, probably, developed soon after 
the stage figured in textfig. 6. A stage, in which the velar plate 
has just been opened, possesses three large tentacular bulbs, all of 
about equal size. As mentioned above, the fourth bulb is not devel¬ 
oped until after the liberation of the medusa. — The development 
