NO. 1 TAYLOR: PACIFIC MARINE ALGAE 185 



in series on one side of a branch, single on each segment, or a second on 

 the opposite side, extremely prominent, 0.18-0.20 mm diam., to 0.25 mm 

 tall, rounded. 



J. E. Gray 1867, p. 33, figs, a, b; Anderson 1891, p. 217 (as Amphi- 

 roa Aspergillum) ; Manza 1937a, p. 45; Smith 1944, p. 231, pi. 53, fig. 

 3. 



Mexico: Baja California, in small amount among tufts of Corallina, 

 South Bay, I. Cerros, no. 34-645B, 10 Mar. 1934. 



AMPHIROA Lamouroux, 1812 



Basal part usually a small disk, which bears erect branches di- or 

 trichotomously divided, usually terete, but sometimes flattened or show- 

 ing a thicker midrib and a thinner margin, divided into calcified segments 

 alternating with flexible articulations ; conceptacles lateral, sunken in the 

 branches, often somewhat projecting. 



Suneson 1937, p. 46. 



KEY TO SPECIES 



1. Branches throughout cylindrical or a little compressed, especially 

 below a fork 2 



1. Branches flat above, although the segments very near the base of 

 the plant are commonly cylindrical or only compressed . . 8 



2. Plants of various sizes, but the flexible joints not particularly 

 distinctive 3 



2. Plants with the flexible joints conspicuous, blackish ... 7 



3. Segments nearly cylindrical throughout, except sometimes below 

 the forks 4 



3. Segments commonly compressed, especially below a fork . . . 

 A. franciscana 



4. Conceptacles single on each fertile segment, or at least only one 



on a side, relatively large A. minutissima 



4. Conceptacles relatively smaller, commonly several in the length 

 of a fertile segment 5 



5. Plant with branches reaching only 0.5 mm diam. . . A. annulata 



5. Plant with the upper branches reaching 0.6 mm diam., the lower 

 portions reaching 1.2 mm diam 6 



6. Segments 2-4 diameters long; plants to 4.5 cm tall . A. mexicana 



6. Segments 5-7 diameters long; plants to 10 cm tall . A. peninsularis 



7. Plants turf like, about 2-3 cm tall A. galapagensis 



