73 



THREE UNDESCRIBED CALIFORNIAN ALGM. 

 By W. G. Farlow. 



Dictyopteris zonarioides Favlow. Haliseris polypodioides 

 McClatchie Proc. Southern California Academy, I, 354. Exs. 

 Phycotheca Boreali- Americana No. 581. 



Fronds dingy brown or blackish arising from a stupose base, 

 densely and irregularly dichotomous, divisions without lateral veins, 

 midrib tomentose, percurreut, laminae soon disappearing below, 

 much incised and lacerate above, ultimate dichotomies short, 

 broader than the lower ones, often subflabellate, tips short, obtuse, 

 or slightly retuse, rather divergent. Tetrasporangia (gonidangia) 

 numerous in sori parallel to the midrib on both sides of the frond, 

 75-100 /J- in diameter. 



Santa Barbara, Dr. Dimmick, Mrs. Cooper; San Pedro, common 

 on rocks just below low water mark, Setchell, McClatchie; San 

 Diego, Cleveland, Mrs. Snyder, Farlow. 



This perplexing species has been known since 1875, when it was 

 first found by Dr. Dimmick at Santa Barbara. Specimens have 

 been seen by me collected from November to June, and, as those of 

 the latter month appeared to be young, it is probable that the 

 species is to be found throughout the year. The earlier known 

 specimens not being in good condition, their denuded bases and 

 flabellate extremities caused them to be regarded as old and atten- 

 uated forms of what is generally known under the name of Zonaria 

 Tournefortii on the Californian coast. On the other hand, young 

 specimens found later passed with collectors for the young of some 

 species of Fucus to the evesiculate forms of which they bear a cer- 

 tain resemblance. When in good condition, however, the percurrent 

 midrib and the special growth by means of a small number of 

 initial cells show conclusively that the alga is a Dictyopteris. 

 Cross sections show the two internal layers of colorless cells, 11—15 

 fj. in diam. with a single layer of colored cortical cells found in the 

 laminse of other species of the genus as well as the scattered tufts of 

 hairs found in most phseosporic algse. The description given above 

 applies to the fully-developed plant which is usually between three 



Erythea, Vol. VII, No. 8 [1 August, 1899]. 



