382 Mr. J. Ralfs on the Nostochinee. 
Sporangia oblong, three times longer than broad, much broader 
than the ordinary cells, one or two on each side of the vesicular 
cell, the outer ones generally smallest. 
The best distinctive mark of this species is the subacute extre- 
mities, combined with the short filament and littoral habitat. 
There are rarely more than one or two groups of enlarged cells ; 
when only one is present it is situated near the centre of the 
filament. I believe that the attenuated extremities are constant, 
at least in the young plant, unless the filament has been broken. 
The var. 8. differs i havmg much slenderer filaments: I am 
not sufficiently acquainted with it to determine whether it be, as 
Mr. Thwaites supposes, a distinct species. 
PuaTteE VIII. fig. 7. a, 6, ordinary form; ¢, var. 8. 
2. S. Jacobi (Ag.). Filaments elongated, their ends usually attenu- 
ated ; ordinary cells subspherical ; vesicular cells spherical ; spo- 
rangia oblong or cylindrical. Spherozyga Jacobi, Agardh, Icones 
Algarum Europearum! ; Berkeley in Eng. Bot. t. 2826. fig. 2. 
Upper Mill, Dolgelley ; near Swansea, J. R. Durham Down near 
Bristol, Mr. Thwaites ! 
Carlsbad, Agardh! Madeira, Rev. T. Salwey. 
Spherozyga Jacobi occurs in thick bluish green gelatinous 
masses, from which the filaments issue in long rays. The fila- 
ments are moniliform, elongated, and generally taper at their 
ends. Ordinary joints at first somewhat quadrate but finally 
orbicular, the terminal one longer than broad and usually coni- 
cal. Vesicular cells spherical, larger than the ordinary joints, 
but not so broad as the sporangia. Sporangia oblong or cylin- 
drical, one or two on each side of the vesicular cell. 
Agardh’s figure represents his Spherozyga Jacobi as having 
the ordinary joints closely united, m fact separated merely by 
transverse dissepiments, and consequently so unlike the present 
plant, that I should scarcely have suspected their identity if 
Mr. Borrer had not afforded me an opportunity of examining an 
authentic Carlsbad specimen which he received from Agardh 
himself. 
Spherozyga Jacobi in some respects agrees with S. Carmichaelit; 
but the filaments are stouter and more elongated, the ordinary 
cells are more orbicular, its habitat is also different, and the dried 
plant wants the opake verdigris appearance so usual in the latter. 
The orbicular ordinary and vesicular cells distinguish it from 
S. elastica and S. leptosperma. 
Puate VIII. fig. 8. a, immature filament ; 6, mature state. 
3. S. elastica (Ag.). Filaments moniliform, dissepiments conspi- 
cuous ; ordinary cells quadrate ; vesicular ones elliptic ; sporangia 
