DUBLIN - UNIVERSITY ZOOLOGICAL AND BOTANICAL ASOOCIATION. 143 
cell, and tlie cell-lip is still simple. The operculum, however, is reduced 
to a curved spine. In M. Buskii the lip is more projecting, and the 
calcareous plate which partially covers the cell-mouth is tuberculated. 
The lateral avicularium is slightly depressed, though still opposite the 
upper third of the aperture. The opercular spine is again expanded. 
M. tricellata closely resembles the last in habit, but the tuberculated 
plate round the mouth is still more fully developed, the lip is more ele¬ 
vated, and the much smaller lateral avicularium is below the cell-mouth. 
The operculum is again reduced to a rudimentary spine. 
M. cyathus is binate, the cell-mouth large and simple, as in M. ter- 
mta; the lateral avicularium very large half way down the cell-mouth. 
The operculum once more expanded and branched. It almost requires 
a microscope to distinguish M. crystallina ( Gray) from the last, they are 
so similar in habit and general appearance; but in M. crystallina the 
expanded operculum is again absent, the lateral avicularia are reduced 
in size, and seated near the base of the cell, and the cell-mouth is again 
contracted by a granular calcareous plate. 
The right of this genus to the name of Menipea depends upon the 
retention in it of the six-celled species, M,cirrata(Lamx.), of the propriety 
of which I think there can be little doubt. The general character is still 
remarkably the same. In M. cirrata a smooth plate covers the cell aper¬ 
ture, the lower part calcareous and fixed, the upper portion a movable, 
crescentic, homy operculum, closing over the true opening. I have not 
seen M. Patagonica (Busk), and from the figure I am more doubtful as 
to its position. All the species are distinguished by the presence of one 
or more sessile avicularia on the front of the cells, and by the remarkable 
hollow curved spines attached round the upper lip of the cell-mouth by 
horny joints. 
This group does not seem to “ fruit” freely. I do not know the ovi- 
cell even in our common British species, M. ternata (j Ellis) ; but fortu ¬ 
nately Dr. Harvey’s collection contains a branch of M. Buskii from 
Bass’s Strait, bearing several: globular, the surface granulated, im¬ 
mersed among the cells in the middle of the internode. One can scarcely 
doubt that all these closely allied forms have similar reproductive organs, 
and, if so, the ovicells will give an excellent generic character. 
M. triseriata (Busk) and M. multiseriata (Busk), which have their 
ovicells galeate and superior, like those of Scrupocellaria, must seek other 
congeners. 
I do not consider it necessary to subdivide the genus. 
1.— 1L cyathus, n. s. Plate XY., Figs. 10, 10a. 
Cells very short and round; two in each intemode, one a little 
above the other cell-mouth; large, oval, oblique; rim slightly thickened, 
five to six spines round the upper and outer margin; the lower three, 
large, curved, hollow, and pod-like, attached by a horny joint to the 
thickened lip. Opercular spine expanded, branched, spreading down¬ 
wards and outwards from the upper and inner lip of the cell-mouth. A 
