492 Howe: Phycological studies 



Cladophora ovoidea Kiitz. (type from the island of Fohr, North 

 Sea) has, according to its original describer, primary filaments that 

 are 1/20'" (H2jli) thick and upper branches 1/40'" (56^) thick,* 

 and his laterf figures of the species bear out this general description 

 of its dimensions, though one of the cells of the main filament 

 figured, according to the magnification given, reaches a diameter 

 of 150/z. 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 

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

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

 scribing any of the cells as "ovoid" (Kiitzing, Phyc. Gen. 266). 

 Also, according to Kiitzing's figure, 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. 



Cladophora trichotoma (Ag.) Kiitz. Sp. Alg. 414. 1849 

 Conferva trichotoma Ag. Syst. Alg. 121. 1824. 



Fragments referable to this or to some closely allied species 

 are mixed in with a specimen of Centroceras clavulatum from La 

 Paz in the herbarium of the New York Botanical Garden, ex herb. 

 C. L. Anderson, collector unknown. The intertangled filaments 

 are 190-300/i in diameter, di- or trichotomous at nearly every 

 joint, with occasional short and blunt lateral branches 1-3 cells 

 long and of scarcely less diameter than the parent filament; cells 

 mostly 2-5 times as long as broad, usually constricted at the 

 septa, the upper often ovoid. The plants are rather coarser and 

 the cells are relatively shorter than called for by Kiitzing's descrip- 

 tion and figures for the species in question. 



Halimeda discoidea Decaisne, Ann. Sci. Nat. II. 18: 102. 1842. 

 Howe, Bull. Torrey Club 34: 495-500. pi. 25.}. 11-20; 



pi. 26. 1907 

 La Paz, Vives 4. 

 The segments are here mostly quadrangular-oblong or cuneate- 



* Kiitzing, Sp. Alg. 393. 1849. 



t Kiitzing, Tab. Phyc. 3: 26. pi. 92. f. I. 1853. 



