268 THE MARINE BOTANIST. 



Tetraspores \eTj minute, secund on the upper 

 ramuli. Grows on the larger algae near low water- 

 mark, frequent. Annual. Summer. 



CALLITHAMNION BRACHIATUM.—SLEN- 

 DER SQUARE-BRANCHED CALLITHAM- 

 NION. 



This plant very much resembles C. tetragonum, 

 but differs from it in outward character in its more 

 slender habit and lanceolate outline ; microscopically 

 it is distinguished by the ramuli gradually tapering 

 to a fine point, and not as in that species suddenly 

 acuminate. It is found in the same situations as 

 the C. tetragonum, and is equally common. 



CALLITHAMNION BORRERL— BORRER'S 

 CALLITHAMNION. 



From less than half an inch to four or five in 

 height, tufted, much branched ; branches set with 

 plumules which are without ramuli along their 



