46 STRETHILL WRIGHT, ON BRITISH ZOOPHYTES. 
Z&iquorea of our coast to any true hydroid. But the structure 
of Aiquorea in its adult Medusa state is so strictly homolo- 
gous to that of all the naked-eyed Meduse, that even if it 
were ascertained that it undergoes a direct metamorphosis 
from the egg to the perfect Medusa, I would not hesitate to 
consider it as a member of the order of Hydroids, since it has 
simple, radiating, aquiferous tubes, a circular canal, and mar- 
ginal tentacles closely connected with it, and provided with 
minute pigment-spots at the base.””? Agassiz was doubtless 
correct, and he might also have predicted that it belonged to 
the genus Campanularia or Laomedea, as it corresponded with 
the Medusoids of those genera in the presence of otoliths, 
while the Medusoids of the Tubularian hydroids hitherto ob- 
served, are destitute of those appendages. In the begin- 
ning of this month (November) Mr. Fulton sent me two living 
specimens of A/quorea vitrina (Pl. IV), one about three inches 
in diameter, the other about six inches and a half. The number 
of lips of the latter was about forty, the radiating canals, each 
having a long, double ovisac, about eighty, and the marginal 
tentacles, by estimation, four hundred. On examining the 
ovaries, I found that the eggs were hatched, and the young, 
in the form of almost invisible planulz, were issuing from the 
ovisacs. These were gently extracted with a glass syringe, 
an instrument so useful to those who practise the obstetric 
art amongst the Hydroidz, and were placed about three weeks 
ago in glass tanks of clean sea-water prepared for their re- 
ception. Many thousands of larve were placed in the tanks, 
and of those about a score have been developed into Cam- * 
panularian polyps; about a hundred are still progressing to 
that end, and the rest have disappeared. It was with no little 
impatience and anxiety that I saw the planula during a fort- 
night fix itself to the glass, spread itself out into a short 
thread, secrete its scleroderm, put forth its polyp-bud—this 
last slowly swelling day by day, until at last it opened, and a 
polyp appeared, furnished with twelve alternating tentacles, 
joined together for about one third of their length by a web, 
the polyp enclosed in a cell terminating m many acuminate 
segments. It is now about six years ago that I was watching, 
in like manner, the slow evolution of a bud from a Campanu- 
larian zoophyte, the Laomedea acuminata of Alder, the bud 
opened, and a bright-green Medusoid issued forth, having 
four lips and two tentacles.* The hydroid phase of Aquorea 
vitrina is, as far as I can determine, identical with that of 
L. acuminata in shape; but is so excessively small—quite 
* ¢Hdin. New Phil. Mag,’ vol. vii, N. S., p. 110. 
