ULVACE^. 65 



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 difiicult 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 indifierently 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. B XffGi A. vermicular is, 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 difiicult, in this part 



