212 University of California PuMications in Botany [you 8 



Collins, in Khodora, vol. 11, 1909a, p. 19, pi. 78, f. 6. CladopJwra 

 erecta Collins, in Collins, Holden and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. 1690. 



Cladophora gratninea is one of the coarsest of our west coast 

 species of erect Cladophoras, superficially resembling a species of 

 Spongamorpha in this and in its habit. It has been usually confused 

 with C. cartilaginea which, properly, is a Spongomorpha. In its regu- 

 lar or unequal, dichotomous branching, where each arm is composed 

 of a single segment, in its coarseness, as well as in the proportional 

 length of the segments, it is to be distinguished from all our other 

 species. 



5. Cladophora microcladioides Collins 



Plate 13, fig. 2 



Plants more or less densely tufted, 10-20 cm. high ; filaments about 

 200/x diam. at the base, segments 4-6 diam. long; stiff, straight or 

 flexuous, distantly di-trichotomous, branches similar, erect or more 

 or less recurved, bearing on the upper (inner) side numerous short 

 branches, rarely with very short branches opposite one or more of 

 them; this ramification continued, the ultimate ramuli of very few 

 segments, 80-100/x diam., segments 1.5-2.5 diam. long. 



Growing in the upper sublittoral belt. From Vancouver Island, 

 British Columbia, to San Diego, California. 



Collins, in Rhodora, vol. 11, 1909a, p. 17, pi. 78, f. 2, 3, Mar. Alg. 

 Vancouver Island, 1913, p. 104. 



Cladophora microcladioides f . stricta Collins 



Similar to the species but differing in habit ; branches of various 

 orders virgate and little recurved. 



Lower littoral belt. San Diego, California, 



Collins, in Collins, Holden and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. 1583. 



In its typical form Cladophora microcladioides is one of our most 

 readily recognized species of the Eucladophora section or erect Clado- 

 pJioras. The regular recurved brajiches give the plant much of the 

 habit of Microcladia horcalis Ruprecht. There is much variation in 

 height, flexuosity of principal axes, frequency of recurved pinnules, 

 etc., but the pinnules are distinctive and usually readily recognizable. 

 In the forma stricta, however, the pinnules are not recurved, but there 

 is more or less of an indication of the close affinity with the species. 



