RED ALG^i. 203 



from January to March, at San Diego, and all the year 

 around, in great abundance, at Santa Cruz and Santa 

 Barbara. 



Order.— SPONGIOCARPE&. 

 Genus.— POLYIDES* Ag. 



POLYIDES ROTUNDUS, AG. 



This is the only species in the genus, and the 

 only genus in the order. Agardh names it P. luvi- 

 bricalis, but rotundas appears to be the older name. 

 The frond is cylindrical, and rises from a minute 

 disk, at first very slender, then thickens, and at the 

 height of an inch, or an inch and a half, is as large 

 as a knitting-needle, where it widely divides or forks. 



In the course of half an inch more, each of 

 the branches forks in the same way ; a little further 

 on, all these fork, and again these branchlets, till 

 there arc six or eight regular dividings, each succes- 

 sive one being less wide and spreading than the one 

 immediately before it. This gives the plant a fan- 

 shaped outline. The branches all keep their cylin- 

 drical form, so that the plant looks stiff and bare, 

 notwithstanding its much branching. 



• Polyidea — Many-formed. 



