vine: YORKSHIRE CARBONIFEROUS AND PERMIAN POLYZOA. 189 
The gonocysts of this species are described and figured for the 
first time. They consist of small inflated sacs, which occupy various 
positions on the stem, and not always in a line with the growing part 
of the same. In the course of my investigations I have gathered 
together a rather large assortment of these " o^acells," but in every 
case their characters are similar. Two of the best of these are 
figured (pi. vii., fig. 1) as placed on the side of the stem. The sac is 
oval, and the lateral vestibule on the right hand side is pushed out 
of position, while the "network" of tlie stem is, on the base especially, 
interwoven with the sac. The orifice of the gonocyst of this example 
is very perfect, and is bordered by a slight rim, and just below the 
orifice is a second " opening," much smaller in size, the function or 
purpose of which I cannot make out, but otherwise the " orifice " 
proper is very characteristic, and is on a par with the ovicells " of 
Cyclostomatous species already figured by authors. The second 
example, (pi. vii., fig. 2), is similar in every respect, excepting the slightly 
zig-zag orifice which may or may not represent an abrasion, but the 
''opening" below is more perfect in this example. The "ovicell" is, 
as wil] been seen, apparently reversed. Other gonocysts of this 
species are placed in the angle formed by the branches. These are 
similar to those described above, and the "network" which envelop 
the sac is like that of the reverse rather than of the inter-vestibular 
spaces, but no reliance can be placed upon this variation of character 
for specific or descriptive purposes. I have, however, sectioned an 
example which has been formed in the angle of the branches (pi. vii., 
fig. 3), and the peculiar mode of attachment of the " network" to the 
stem, and also the orifice are very well shown in the figure. The 
examples described are characteristic and typical " ovicells " of 
Hyphasmopora generally. 
I do not think that there can be any question respecting the 
function of these peculiar sacs, but in all honesty, though I may be 
the first to figure and describe them, I believe that both Mr. Ether- 
edge, jun., and Mr. John Young, of Glasgow, have noticed the 
" growths" on some of these fragments of Hyphasmopora, though 
they may not have noticed similar " growths" on other Carboniferous 
species. 
