filaments several times longer than broad, of the upper branches gradually 
shorter, and the uppermost joints extremely short. Dissepiments coated 
with a broad, coloured band of minute cellules, more or less clearly defined, 
furnished with a regular whorl of robust, subulate, colourless prickles, 
composed of three cells or joints, the lowest joint being twice as long as the 
other two; the uppermost very small and acute. Tetraspores not very pro- 
minent, disposed in a whorl round the joint, alternately with the prickles. 
Favella, according to Dillwyn, “ roundish, lateral, nearly sessile, and mostly 
accompanied by three or four, short, incurved ramuli”. Colour of the tufts 
a purplish-red. Swéstance membranaceous and rigid, imperfectly adhering 
to paper in drying. ‘ 
; OO en rr re se ore 
Under the common name c7/iatwm at least three distinct varities 
@ of Ceramium, now regarded as distinct species, have hitherto been 
confounded by British botanists. These I have brought together 
in the present.number for the purpose of contrasting their cha- 
racters. The excellent figures published by Ellis, and Dillwyn, 
and the descriptions given by @ise*authors, leave us at no loss 
to decide to which of the three modern species their synonyme 
belongs. They appear to have had the present species*Solely in 
view. In Herbaria, on the contrary, the thré§are very frequently 
confounded together, and even in the excellent work of Mrs. Wyatt, 
specimens of C. echionotum are published in some of the copies, 
as C. ciliatum. ° 
It is but just to state that my accurate friend Mrs. Griffiths 
has for many years been convinced of the distinctness of these 
plants and separated them in her own rich collection; and one of 
them was also well distinguished by the late Capt.Carmichael. To 
the naked eye they have very much the same appearance, and to _ 
the touch the same peculiarly harsh feel, and it is not till we | 
submit small portions to the test of the microscope that their — 
differences are perceived. Obvious differences may then be ob- 
served in the spines, with which the joints are armed, and these 
appear to be constant. 
Fig. 1. CeERAMIUM CILIATUM; tuft, of the natural size. 2. Portion of a filament. 
3. Apex of the same. 4. A joint with tetraspores. 5. A prickle:—adl 
more or less highly magnified. . 
