with wide margins, sessile on the sides of short, simple, or branched peduncles, 
which rise from the ramuli near their base. Favelle mostly bilobed, invo- 
lucrate, borne on lateral peduncles, or terminating shortened ramuli. Suéd- 
stance flaccid, adhering to paper. Colour a fine rose red, soon fading in 
fresh water. Sometimes the ramuli are alternate, and then the plant be- 
comes C. repens of authors. 
een nn ee a eee eee 
This pretty little species of Callithamnion was named by Dr. 
Roth after its discoverer Mr. Dawson Turner, the celebrated 
author of the Historia Fucorum and numerous other learned 
works. It was first observed on the Norfolk coast; and has 
since been found on most of the shores of Europe, where it not 
uncommonly creeps over the fronds of various small Alge. 
After as careful study as I have been able to give the subject, 
I am persuaded that Cal. repens of authors is nothing more than 
an imperfectly developed state of this species, in which either the 
plant is m a very young state, or, if more fully grown, the branches 
are mostly alternate. I have examined numerous specimens in 
which the alternate and opposite branching occurs in different 
parts of the same specimens; and as this is the chief character 
insisted on by those who contend for two species, its failure must 
destroy one of them. The form which has been called C. Turneri 
exhibits the species in its most perfect state, and therefore this 
name, apart from its commemorative significancy, deserves to be 
retained. 
The fructification of this species differs in some respects from 
that of other Callithamnia, and shows an approach to Grifithsia, 
especially in the involucrated favelle. The tetraspores are, how- 
ever, not so regularly disposed as in that genus; and the habit 
is much more like that of Callithamnion. 
Fig. 1. CALLITHAMNION TURNERI:—of the natural size. 2. Branch with 
tetraspores. 3. Portion of the same. 4. A tetraspore. 5. Portion of a 
filament with favelle. 6. Ramulus and pedunculate favella. 
