ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
49 
/?. Lopbonemata. Tentacles simple and arranged in tufts. 
9. Bougainvilleidse. Stalked indicating knobs at oral margin ; 
Margelis, Hippocrene, and BalhJcea. 
y. Cladonemata. Tentacles compound, pinnate or branched. 
10. Pteronemidaa. Tentacles pinnate; Pteronema, Ctenaria, 
Zanclea, and Gemmaria. 
11. Dendronemidre. Tentacles branched ; Cladonema and 
Eleutheria. 
Saphenia mirabilis.* — Among the valuable rarities lately found 
near Plymouth, Mr. J. T. Cunningham records this interesting 
Medusa, several hundreds of which were obtained. Called Goodsiria 
mirabilis by Strethill Wright, who found three specimens in the Firth 
of Forth, it has never again been seen till now ; and its hydroid stage 
still remains to be discovered. 
Myriothela phrygia.f — Mr. W. B. Hardy has had the opportunity 
of studying this interesting hydroid at Plymouth. In the proximal 
or gonophore-bearing region of the blastostyles the ectoderm is com- 
posed of varied elements, and differs in appearance at different seasons. 
It is most complex and thickest in spring and early summer, but in 
autumn it is not only much thinner, but presents the appearance of 
being exhausted. A characteristic feature of the spring ectoderm is 
the presence of small cells, which disappear in the autumn ; the 
author cannot but think that their disappearance is connected with 
the active formation of gonophores during the summer months. These 
special small cells occur in little groups, and frequently betray signs of 
active proliferation. As they are absent from other parts of the body, 
and have a peculiar relation to the gonophores, they may be justly 
looked upon as preformed sexual elements. The process of bud- 
ding appears to be somewhat remarkable ; when a bud is about to 
be formed the ectoderm-cells lose their defined characters, proliferate, 
and give rise to a bulging mass of amorphous tissue ; the thick 
supporting lamella becomes absorbed, and the endoderm cells likewise 
proliferate and take on an amorphous character ; the result is a 
kind of blastema in which the limits of ectoderm and endoderm are 
not to be distinguished. As this grows the elements lose their dis- 
tinctness and become highly charged with spherical masses of stored 
nutriment, resembling in many points the nutritive spheres of the 
general endoderm. From this the young Myriothela, which early loses 
all connection with the body of its parent, is developed. 
In its early stage the formation of a gonophore is essentially 
similar to that of a bud, but in this case a group of the primitive germ- 
cells make their way into it. These primitive cells pre-exist as free 
cells, having lodgment in the tissues of the adult, and only travel into 
the abortive bud (gonophore) which is their place of final development. 
At first the male are indistinguishable from the female gonophores. 
Mr. Hardy gives a detailed account of the endoderm of Myriothela, 
which may be divided into several regions. There is an oral region 
characterized by the presence of sense-cells and cilia in its upper part 
* Journ. Mar. Biol. Ass., ii. (1891) p. 194. 
t Quart. Journ. Micr. Sci., xxxii. (1891) pp. 505-37 (2 pis ). 
1892. 
E 
