1920] Setchell-Gardner : Chlorophyceae 215 



about one half the diameter of the filaments from which they spring, 

 usually 3-7 segments long, in most cases gradually tapering from 

 near the base, subacute or blunt, commonly rather rigid ; segments in 

 extreme basal parts 6-15 times as long as broad, in median and upper 

 parts 1-4 (mostly 1.5-2.5) times as long as broad, usually a little 

 constricted at the septa and appearing quite strongly constricted 

 when dry. 



San Felipe Bay, Lower California. 



Howe, Phyc. Studies V, 1911, p. 491, pi. 33, f. 7. 



Collins (Green Alg. Suppl. I, 1912, p. 96) appends the following 

 note to C. ovoidea, "This species," referring to C. MacDougulii, "is 

 compared by its author with C. Hutchiiisiae (Dillw.) Kiitz., and C. 

 0voidea Kiitz., but is considered distinct from both. A specimen 

 kindly furnished by the author shows that it is amply distinct from 

 the C. Hutchinsiae of England and France, N. J. and Barbados. It is, 

 however, quite close to the California plant given as C. ovaidea by the 

 writer, 1909, p. 346, and would have been placed there without ques- 

 tion. It may well be that it is distinct from the C. avoidea of Europe, 

 which appears to be a little known species. The California plant is 

 larger in all dimensions, less moniliform, and with long excurrent axes. 

 A comparison of specimens from various stations shows much varia- 

 tion in the two last particulars, but all are much stouter than C. 

 ovaidea as originally described. It often varies in the direction of 

 C. microcladioides Collins, with denser and more fasciculate branch- 



ing." 



Howe says (1911, p. 492) : "We have seen no European specimens 

 of C. ovoidea, but are unwilling at the present time to identify with 

 this species a Lower California plant with filaments and branches 

 averaging twice as thick as those of the plant described and figured 

 by Klitzing, and with filaments so little constricted at the septa (in 

 a soaked out condition, at least) that no one would think of describing 

 any of the cells as 'ovoid' (Kutzing, Phyc. Gen., 266). Also, accord- 

 ing to Kiitzing's figure (Tab. Phyc, 3:26, pi. 92, f. 1, 1853), the 

 branching in C. ovoidea is more fasciculate than in C. MacDougalii, 

 the ultimate lateral branchlets are less tapering and less rigid, and 

 the main axes do not show the long-excurrent prolongations of the 

 Baja California species." 



It seems best to us to retain C. MacDougalii as a distinct species. 



