instance, materials about which there could be no mistake; but 
I have not been able to find, on the portion examined, the 
axillary tetraspores which that observer describes. Such cha- 
racters as the barren filaments supply are faithfully given in the 
annexed plate. 
Fig. 1. Tufts of CALLITHAMNION SPARSUM, growing on an old stem of Lami- 
naria:—natural size. 2. A few fronds from one of the tufts. 3. Portion 
of a branch :—more or less magnified. 
