270 



ALLAN HANCOCK PACIFIC EXPEDITIONS 



VOL. 12 





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ing from base to apex, the tips of the branchlets erect or forcipate, in the 

 lower parts especially with numerous slender proliferations; diameter 

 below to about 0.75 mm, above about 170 /x,; segments above for quite a 

 distance much shorter than broad, the cortication of each sharply de- 

 limited from the next but without a definite 

 naked zone; below the segments subequal to 

 twice as long as broad, with the cortication 

 much thinner below than near the top of the 

 segment and cells over the internodes in dis- 

 tinct longitudinal series; reproduction un- 

 known. 



These plants look entirely like young 

 stages of C. rubrum or C. pacificum. The 

 nodal cortication in the young state consists 

 of small angular cells somewhat irregularly 

 disposed, completely covering the node and 

 the short internode, but limited by a very 

 sharp line. As the internode lengthens, the 

 nodal cortication spreads downward, the cells 

 being at first rectangular, in very distinct 

 rows. When the full growth of the axis is 

 reached, however, the cortication over the 

 lower part of the internode is thin ; some cell 

 rows do not reach so far, the cells are more 

 elongate and narrower, but still clearly in 

 rows, and there is exposed no regularly naked 

 segment of internode. Furthermore there is 

 almost no upward growth of cortication from 



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Text Figure 1. Ceramium hoodti. The median 

 portion of an older segment showing the longi- 

 tudinal "filaments" well extended, at the lower end 

 rather unusually irregular. The upper margins of 

 two nodal zones appear, showing the small amount 

 of cortication developing from this margin and 

 consisting mostly of elongate cells, not segmenting 

 "filaments." x 235. I. Espafiola. 



