276 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 3 



D. & R. 3233, 3328, intertidal pools in vicinity of Guaymas, Dec; 

 D. 394, Tepoca Bay, Feb. ; D. 320, Gonzaga Bay, Feb. ; D. 225, Puerto 

 Refugio, Jan. ; D. 460, San Esteban Island, Feb. 



Genus AMPHIROA Lamouroux 

 Amphiroa pusilla Yendo 



Yendo, 1902a, p. 13, pi. I, figs. 22, 23, pi. V, figs. 11-13. 



Several collections are on hand of an Amphiroa of variable form 

 vi^hich in many respects seems to be referable to the Japanese plant de- 

 scribed by Yendo. Two forms are present as well as many intermediate 

 variants: a loosely branched, broad segmented, more or less decumbent 

 form, and a densely tufted, erect form in which the segments are largely 

 attenuated in the upper parts, ending in a blunt, rounded tip. These 

 characters correspond to Yendo's description, and his figures show much 

 resemblance to the Gulf plants. The extreme variability of our specimens 

 and the limited knowledge of the distribution of the species must make 

 this plant subject to much further inquiry. 



The various forms make up an abundant rock cover in many shore 

 localities in the northern Gulf: D. 717, Turner's Island, July; D. 222, 

 Puerto Refugio, Jan.; D. 112, Tiburon Island, Jan.; D. & R. 3387, 

 3390, 3325, 3330, vicinity of Guaymas, Dec. 



Amphiroa zonata Yendo 



Yendo, 1902a, p. 10, pi. I, figs. 11-14, pi. IV, fig. 9. 



Specimens of several Gulf collections correspond excellently to Yen- 

 do's descriptions and figures of this plant. Its regular, dichotomous 

 branching and cylindrical to slightly compressed segments with very dis- 

 tinct transverse banding of the terminal segments are distinctive charac- 

 ters. 



These plants are not abundant in the collections at hand, but occur 

 occasionally in material from a number of shore localities: D. 717, Tur- 

 ner's Island, July; D. 222a, Puerto Refugio, Jan.; D. & R. 3386, Punta 

 San Pedro, Guaymas, Dec; D. 485, Catalina Bay, Guaymas, Feb. 



Amphiroa rigida Lam. 



Lamouroux, 1816, p. 297, tab. 11, fig. 1 ; B0rgesen, 1915-20, pp. 182-185, 

 figs. 171, 172 (var. antillana). 



