SOME NEW ALGÆ FROM JAPAN. 281 



towards the base, and the apex is roundish. The largest specimen 

 in my possession measures 25 cm. in length and 5 mm. in its 

 maximum diameter. The surface of the frond, all but the lower 

 portion, is dotted with minute conical processes. The colour of 

 the fronds varies from an olive brown to a brownish yellow, 

 very likely due more to the age than to the condition of habitat 

 of the plant. 



The internal structure of the frond agrees with that of Chor- 

 daria abietina in its essential points. The narrowed basal part 

 is solid for a short distance, and is constructed of three sorts of 

 tissues. The central axis is composed of strands of fibrous hyphæ 

 running straight upwards, and it occupies but an insignificant part 

 of the whole structure. The cortical part around the axis oc- 

 cupies more than half of the radius in a section. It consists of 

 thin-walled, cylindrical cells, 3—6 times as long as the diameter. 

 The inner strands of the cortex run regularly parallel to the axis, 

 and are straight and simple. The outer ones ramify obliquely 

 towards the surface of the frond to form the peripheral tissue. 

 This consists of several layers of cuboidal cells, compactly dis- 

 posed anticlinally and radially in the external half (Fig. 14). 

 These cells are nearly equal in diameter to the cortical cells at 

 a part near the base of the frond, but become half the width 

 immediately above. 



The structure described above is confined to the solid basal 

 part. The frond becomes hollow at a point a few millimetres 

 above the base. The axial filaments no longer appear to play 

 an important part, being found here and there adhering to the 

 inner surface of the cortex. The cortical cells become irregular 

 in shape and are arranged less compactly than before, with a 

 gelatinous matrix filling up the intercellular spaces (Fig. 15). 

 The cell-rows of the peripheral tissue become disconnected and 

 form the so-called assimilators. 



The minute verrucose processes which characterize the pre- 

 sent species are due to an extraordinary multiplication of the 



