RED ALG^E. 269 



It is scarce at Santa Barbara, from January to 

 August, on the beach, growing parasitical on Micro- 

 cladia and Ceramium rubrum. It is not uncommon 

 at Santa Cruz all the season, parasitical on Ptilota 

 densa. It adheres well to paper, and the younger 

 and smaller plants are certainly very beautiful, and 

 well worth looking for. The color in them is a deep, 

 rich red J of a darker shade in the older plants. I 

 suppose it may be expected in greater abundance 

 farther north. It is no doubt often collected at the 

 Golden Gate. 



Callithamnion heteromorphum, Ag. 



This is by far the most beautiful of the California 

 Callithamnia. It is represented in Figure 2, Plate 

 Xyill. It has a leading stem which extends through 

 the whole plant, giving off alternate branches from two 

 opposite sides at regular intervals. These branches 

 shorten towards base and apex from the middle, where, 

 in a plant two inches high, they are half an inch long. 

 This gives the frond a very perfect lanceolate outline. 

 From the primary, spring secondary branches in the 

 same way, which divide alternately towards the top, 

 in very short branchlets. 



The peculiar mark of the species is the little circlet 

 of delicate plumes which adorns the top of every 

 joint, in the stem and branches, from the base to the 



