NO. 1 TAYLOR: PACIFIC MARINE ALGAE 299 



four to twenty-four pericentral cells of equal length, and sometimes corti- 

 cated by rhizoidal downgrowths; branched colorless trichoblasts some- 

 times present ; tetrasporangia single in the fertile segments, forming con- 

 siderable series in little-modified branches; spermatangia in colorless 

 elongated cylindrical to spindle-shaped clusters developed on a trichoblast 

 rudiment; procarps also developed on trichoblast rudiments, producing a 

 carpogenic branch of four cells vrith auxiliary and sterile cells ; after ferti- 

 lization the pericarps sessile or short stalked, large, globose, ovate or sub- 

 urceolate, ostiolate. 



KEY TO SPECIES 



1. Pericentral cells 5 or less 2 



1. Pericentral cells more than 5 4 



2. Plants erect 3 



2. Plants small, matted or tufted; pericentral cells 4; trichoblasts 

 present; branch tips incurved P. decussata 



3. Pericentral cells 3-5 ; trichoblasts evanescent ; branch tips straight 

 P. homoia 



3. Pericentral cells 5; trichoblasts absent; branch tips forcipate . 

 P. bifurcata 



4. Plants erect; pericentral cells 12 P. Hendryi 



4. Plants small, creeping, the tips often curved; pericentral cells 10 



or 12 P- Howei 



Polyslphonia homoia Setchell & Gardner 



Setchell & Gardner 1930c, p. 162. 



Plants to 20 cm tall, soft, rose red, the lower branching pseudodichot- 

 omous at wide angles, the upper alternate and ascending with the nu- 

 merous main axes somewhat excurrent; branches arising axillary to the 

 subsimple evanescent trichoblasts, contracted at the base, gradually 

 tapered to the apex with prominent apical cells and considerably delayed 

 longitudinal division of the segments; in section the stem with 5 pen- 

 central cells below, ecorticate, reaching a diameter of 370 /*, the segments 

 480-550 fi long; in the middle portion of the plant the diameter is about 

 180 IX, the segments 480-600 /x long and twisted through as much as 

 100°; upper branches probably with 4 pericentral cells, the diameter 

 about 65 fi, the segments about 70 fx long ; tetrasporangia in series of about 

 4 in a branchlet, 90-120 [x long, 75-90 /x diam.; cystocarps showing a 

 short-stalked turbinate to truncate-conical pericarp, the apex not pro- 

 duced, 240-320 IX diam., 280-320 fx long. 



