NO. 10 DAWSON : MARINE ALGAE, GULF OF CALIFORNIA 203 



terfal can, as Setchell and Gardner indicate, only doubtfully be referred 

 to this form-name (E. tubulosa), though some of the specimens at hand 

 may very well fall under E. prolifera. The forms which best correspond 

 with E. compressa are common and fairly consistent in morphology. 



Enteromorpha acanthophora Kiitz. 



Kiitzing, Tab. Phyc. VI, pi. 34; Setch. k Gard., 1924, p. 715, pi. 16, 

 fig. 43, pi. 38. 



Considerable variation in size and proliferation is present among the 

 many collections of this species, which may best be recognized by the 

 abundance of short, spinelike proliferations, longer in lax specimens, 

 shorter in smaller forms with larger tubes. 



D. & R. 3140, 3423, 3288, 3365, 3156, 3139, 3427, on rocks in tidal 

 water, various shore stations near Guaymas, Dec. ; D. 40, Guaymas Bay, 

 Jan.; J. 39, lower littoral rocky beach, Los Angeles Bay, June; D. 374, 

 dredged from 22 meters, Tepoca Bay, Feb.; D. 418, in lagoon. Pond 

 Island, Feb. ; D. 470, dredged in 30-36 meters, near Guaymas, Feb. ; D. 

 604, shallow lagoon, San Gabriel Bay, Espiritu Santo Island, Feb. 



Enteromorpha compressa (L.) Grev. 



Greville, 1830, p. 180, pi. 18; Setch. & Gard., 1920, pp. 251-252; 1924, 

 p. 716. 



This species may be distinguished by its smooth, slender tubes of even 

 diameter, which are nonproliferous and little branched. 



Abundant in tidal water about Guaymas, both floating and attached : 

 D. & R. 3261, 3282, 3321, 3312, 3280, 3428, 3244, 3429, 3245, 3241, 

 3143, 3154, 3153, Dec; D. 56, 65, Jan.; D. 87, dredged in 12-20 meters, 

 outside Guaymas Bay, Jan.; D. 152, dredged in 4-32 meters, off Tiburon 

 Island, Jan.; D. 526, high rock pool, Agua Verde Bay, Feb.; Brand. 17, 

 La Paz. 



Enteromorpha intestinalis (L.) Link 



Link, 1820, p. 5 ; Kiitzing, Tab. Phyc. VI, pi. 31 ; Setch. & Gard., 1920, 

 p. 252. Enteromorpha Marchantae Setch. & Gard., 1924, p. 716, 

 pi. 16, figs. 40-42. 

 The forms which best fall under this name are of larger tube-diameter 



than the others known from the Gulf, to 15 mm. in diameter. The tubes 



