18 CRYPTOLARIA CONFERTA. 
sare of the branch. It is possible that this floor disappears with age, and 
that the older hydrothece, where they are immersed in the fascicled stem, 
are without it. In Cryptolaria longitheca, another species occurring in the pres- 
ent collection, the hydrothecx appear to pass continuously into the tubes of 
the hydrocaulus without the intervention of a perforated floor. I have had 
no opportunity of examining the nearly allied genus Grammaria, but accord- 
ing to Sars the hydrothece in this genus form continuous tubes passing un- 
interruptedly into the tubes of the fascicled stem and allowmg of the entire 
retraction of the hydranth from the hydrothece into the tubes of the stem. 
On the branches of the specimen here described there occurred here and 
there certain very remarkable bodies, the real nature of which I have not 
succeeded in placing beyond doubt. They are of an irregularly fusiform 
shape, and at the spots where they occur surround the branch like minute 
sponges. A closer examination shows them to consist of a multitude of flask- 
shaped, apparently chitinous receptacles (Figs. 9, 10), adnate to one another 
by their sides, and springing by a narrow base from an irregular network of 
tubes which encircles the branch, The distal extremity of each is prolonged 
into a free neck-like extension which terminates in an even circular orifice. 
Each receptacle gives exit after a time to a single spherical body, which 
is retained for a period in an external membranous sac connected by a nar- 
row neck to the orifice of the flask-shaped receptacle (Fig. 9, a, a). 
It is scarcely possible not to recognize in these bodies an assemblage of 
true hydroid gonangia, each giving origin within it to a single ovum, which 
is subsequently expelled from its cavity and lodged in an acrocyst in which 
it continues to be for some time retained. 
With the exception, indeed, of there being no apparent hydrothece in- 
tercalated among the gonangia, the bodies in question resemble in all 
essential points a colony of Coppinia. For, just as in Coppinia, we have 
here a colony of mutually adherent gonangia, each containing a sporosac 
with a single large ovum, which after a time is carried out and retained 
within an acrocyst. The absence of apparent hydrothece, however, will 
not allow us to make too close a comparison with Coppinia or to regard 
these enigmatical bodies as constituting a hydroid colony complete in itself. 
Another view, however, suggests itself. May they not represent the 
gonosome of the hydroid with which they are associated? In favor of this 
interpretation it may be urged that nothing else which can be regarded 
as a gonosome occurs in the specimen, and that if we look upon them as 
