362 PROCEEDINGS OP THE AMERICAN ACADEMY 



which I formerly distributed under the name of P. Californica, agree 

 perfectly with tlie type specimens of Harvey in aspect, and also sliow 

 fourteen peripheral cells in a cross-section. The specimens of the 

 Rodgers Expedition adhere well to paper, and bear some external 

 resemblance to certain forms of P. urceolata. A cross-section of the 

 stem shows eleven and twelve peripheral cells, and agrees well with a 

 specimen from California presented to me by Prof. Eaton, where a cross- 

 section of the lower jjart of the frond shows eleven cells. Both the latter 

 show on lateral view six or seven cells ; and, as is also the case with 

 Harvey's type specimens, they are often spirally twisted, as in P. atro- 

 rubescens. The length of the articulations — a specific character, as it 

 seems to me, of very little value in Polysiphonia — is vaiiable. The 

 shape and position of the conceptacles in the specimen given me by 

 Prof. Eaton are very much the same as in the figure of P. gemmifera 

 above quoted. Harvey's specimens of P. gemmifera, as far as I can see, 

 do not differ from those of P. CullJ'ornica of the Rodgers Expedition, 

 except in being shorter, and in the fact that the ultimate divisions of the 

 frond are incurved. 1 think almost any one would agree with Agardh 

 in thinking that the P. gemmifera of Ruprecht is not specifically distinct 

 from his P. hipinnata, which is the older of the two and must take pre- 

 cedence. Under P. bipianala are therefore clearly included the Rodgers 

 Exjj. specimens of P. Califoniica and P. gemmifera, and the specimen 

 of Prof. Eaton. As to the type specimens of P. Oulifornica and Hall's 

 Oregon specimens, although coarser, and differing in aspect from the 

 others, I can find no definite character by which to separate them, since 

 the number of peripheric cells is hardly ever constant when they exceed 

 ten. In this case, Harvey says they are about ten in number, and 

 Agardh twelve, whereas I certainly found fourteen in a specimen of 

 Harvey's. The plan of ramification is the same in each. At any rate, 

 they do not differ from one anotlier more than the forms correctly in- 

 cluded under P. violacea of the east coast. Without a long experience 

 on the Pacific coast, it seems to me unsafe to consider that P. Califor- 

 nica is any thing more than a variety of P. hipinnata, Rupr. I might 

 here remark that the difference in aspect between an alga mounted in 

 fresh and one of the same species mounted in sea water is very great ; 

 e.g., P. violacea. With regard to the specimens in question, I have no 

 means of knowing how they were prepared. 



131. Polysiphonia WooDii, Harv. West coast. — Very distinct. 

 Compressed, showing usually 18-20 perij^heral cells in cross-sections, 

 decidedly more than in P. hipinnata. On a lateral view, the cells are 

 not parallel, but converge towards the base, somewhat as in P. para- 



