NO. 1 DAWSON: MARINE RED ALGAE OF PACIFIC MEXICO 39 



13. Polysporangia oviform; spermatangia secund 



P. squarrosum Kylin 



13. Polysporangia ellipsoidal; spermatangia alternate 



P. vancouverianum J. Ag. 



14. Polysporangia sessile and usually adaxially secund 



P. tohyamanum Tokida & Inaba 3 



14. Polysporangia pedicellate, in groups, not secund 



P. kobayashii Okamura 



Pleonosporium abysicola Gard. 

 PI. 13, fig. 3 

 Gardner 1927a, p. 380, pi. 81, fig. 1, pi. 82. 



Thalli 15-18 mm. high, with 1 or a few percurrent, uncorticated 

 axes 200-235 fx in diam. at the base, with 5 orders of branches, each 

 decidely smaller than the preceding, all branches and ramuli distichous 

 and alternate, arising from every cell, successively reduced but not 

 attenuated, the tips blunt; cells of primary axes and major branches 

 (1.5) 2.5-3.0 diameters long, those in the ultimate ramuli 1-2 diameters 

 long, the basal cells of all orders of branches much shorter than the 

 others, each giving rise to the first branch of the next order on the 

 abaxial side; ultimate branchlets of 2-6 cells; polysporangia elliptical, 

 80-90 jx long, usually 2, sessile and alternate on the subultimate 

 branchlets; spermatangia unknown (modified from Gardner). 



Type: N. L. Gardner 6010, July, in Herb. University of Cali- 

 fornia, Berkeley (296614). 



Type locality: Dredged from 15-20 fms. near Friday Harbor, 

 Washington. 



Mexican distribution: Pacific Baja Calif. — D. 8024, Tanner 

 Bank (70 m.) ; D. 8452, Isla Guadalupe (90 m.) ; D. 9034, Sacramento 

 Reef (57 m.) ; D. 9323, Isla Magdalena, drift. 



This species has been reported heretofore only as the type. Despite 

 the fact that it was described in the absence of polysporangia and the 

 type was described as having much longer axial cells, we attribute 

 these more ample Mexican specimens to this species and have modified 

 Gardner's description. Study of Gardner's type figures reveals that the 

 cells of the principal axes and of the primary branches are for the 

 most part 2.5-3.0 diameters long, although he describes them as 3-4 

 and 4-6 diameters long, respectively. 



Pleonosporium codicolum sp. nov. 

 PI. 14, fig. 4-5 



^Reexamination of a part of the type of P. venustissimum (Mont.) DeToni has 

 shown that Kiitzing's figure was inaccurately drawn and that the branching 

 characters of this species are essentially like those of P. tohyamanum, although 

 the longer axial cells of the former and other features may ultimately be 

 found to distinguish them. (Plate 13, fig. 4) See also Howe, 1914, p. 150. 



