dochrome is at first fluid, but in the full-grown articulations (which are in 
fact changed into sporangia) it becomes distinctly granular, very dense, and 
of a dark colour. In drying the plant adheres to paper, but not very 
firmly. 
The occasional occurrence of this species in salt-water ditches 
near the coast gives it a claim to be admitted into the present 
work, similar to that allowed im the cases of several other of 
these brackish-water plants. C. fracta is rarely found attached. 
It is more commonly met with heaped together in widely ex- 
tending strata, covering the surface of the water. Sometimes in 
lakes, as it thus floats about, it becomes rolled together in dense 
balls, which have a good deal of the aspect of C. egagropila, but 
not the same regularly radiant structure. When fully developed 
and in mature fruit, the middle portion of the frond is very fre- 
quently entirely converted into a string of sporangia, and is 
then a beautiful and characteristic microscopic object, which it is 
impossible to mistake for anything else. When not in fruit, 
C. fracta is more easily known from C. flavescens, which is closely 
allied to it, by the shorter articulations, than by any other 
character. 
Fig. 1. Part of a floating mass of CLapopHora FRacTA :—the natural size. 
2. Branches of the same :—magnified. 3. Small portions in a young and 
a mature state :—highly magnified. 
