ULVACEiE. 
55 
series of very short cells, much shorter than the diameter of the filament ; each con- 
taining an undivided mass of dark purple endochrome, and at this age the whole 
structure is very similar to that of Hormotrichum. When further advanced, the 
endochrome divides longitudinally into many quadrate portions, round each of which 
a cell membrane grows, and they become so many cells arranged in a radiant manner 
round a central point, and appear, when viewed from the side, as transverse rows of 
beadlike granules tessellating the filaments. Eventually, from repeated cell division, 
the arrangement in transverse lines becomes difficult to observe, and the filament looks 
like a confused mass of tissue. The number of transverse granules seen in each row 
depends on age. The figure in Phyc. Brit, represents an old state of the plant when 
the granules have multiplied. The colour under the microscope is a beautiful ame- 
thystine purple. 
I have only received this plant from the above-named American localities, but it is 
probably to be found along the rocky shores of all the northern States. In the British 
Islands it grows indifferently in the sea or in fresh water ; in the latter case it often 
occurs on the walls and gates of canal locks, and it may be expected to occur in similar 
situations in America. The specimen from Newfoundland is in a very advanced 
stage ; the filaments being of large diameter, irregularly constricted, and their granules 
very numerous in each band, and of minute size. The specimen from Lynn, on the 
contrary, is very young, with the transverse rows just beginning to be formed. 
2. Bangia vermicularis , Harv.; root scutate ; filaments basifixed, twisted, setaceous 
at the base, gradually widening upwards and at last claviform, much incrassated toward 
the end, undulating, flaccid, with a wide, hyaline, firm investing tube ; transverse bands 
closely placed ; granules dark-purple, vertically flattened, few in each whorl toward the 
base, very crowded and numerous toward the upper portion of the filament. (Tab. 
XLIX. A.) 
Hab. Golden Gate, California, A. D. Frye (v. s. in Herb. T. C. D.) 
Filaments fixed at the base by a scutate root, and probably freely floating in the 
water ; perhaps tufted, but the specimens received have been pulled asunder. Each 
filament is about two inches long ; at its origin it is of the diameter of human hair ; it 
becomes gradually thicker upwards, until, near the apex, in old filaments, it is at least 
twice as thick as hog’s bristle. The form is therefore linear-clavate, though the club be 
very slender in proportion to its length. When dried the threads look like sinuous 
worms, tapering from a thickened apex to a very slender base. A cross section shows 
a central cavity surrounded by a variable number of radiating, cuneiform, dark-purple 
endochromes. Toward the base of the filament there are but four of these in a plane ; 
a little higher up there are eight, and in the upper portions they are not only indefinitely 
numerous in the whorl, but they form dichotomous radiating strings extending hori- 
zontally from the central tube to the circumference. They do not cohere in regular 
moniliform filaments, but there seems a tendency to do so. It is difficult, in this part 
