General History of the Marine Polyzoa. 169 
some respects very nearly allied to J. ventricosa, Hassall. 
As only a small colony of young cells has been examined, I 
cannot speak with confidence as to some of the superficial 
characters; but the short subrotund and tumid cells, not con- 
tracted above as in J. ventricosa, the large orifice, not raised 
and suberect and closed in by the rather massive peristome 
and spines as in the latter, the three small denticles set 
closely together, the rather slender mucro, and the complete 
absence of striation and marginal punctures are all distinctive 
points. The cells are much smaller than those of MZ. ventri- 
cosa and of delicate texture; but this may be due to the im- 
mature condition of the colony. 
In the absence of more fully developed specimens, I merely 
name it provisionally. It may rank as WV. ventricosa, form 
rotundata, if further evidence should show that it is referable 
to this species. 
Family Membraniporide. 
Memeprantpora, De Blainville. 
Membranipora pilosa, Linneus, form folvacea. 
I have received through Miss Jelly, from New Zealand, a 
specimen of an interesting form of this common and cosmo- 
politan species. It grows as an erect foliaceous frond, with 
the cells disposed on both surfaces and closely united back 
to back. Pallas mentions such a form in his ‘ Elenchus’ as 
occurring in the North Sea* ; but amidst all the varieties of 
this protean species, from various parts of the world, which I 
have examined, it has never occurred to me before. We 
hardly require any fresh evidence to show that such varieties 
of habit are of very small systematic significance. 
EXPLANATION OF THE PLATES. 
Pruate VIL. 
Fig. 1. Mucronella prestans, n. sp. 1a. Zocecium with avicularium ; 
1b. Zocecium, showing the membranous (?) operculum as it ap- 
pears when thrown back. 
Fig. 2. Mucronella conservata, Waters, from a recent Australian specimen. 
Fig. 3. Euthyris obtecta, n. gen. & sp. Group of zocecia, showing one of 
the large cells with moditied orifice. 3a. The same, natural 
size. 
Fig. 4. Flustra reticulum, nu. sp. 4a, Zocecium with avicularium. 46, 
Natural size. 
Fig. 5. Schizoporella latisinuata, n. sp. 
* “Jn frondes lubenter assurgit, utrinque cellulosas, crassiusculas, 
spongiosas; primo simplices. ... deinde ramosas, imo pinnato-multi- 
fidas.”—Llenchus, p. 50. 
