292 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 3 



The Gulf specimens are distinguished from Hypnea pannosa by their 

 larger size and coarser texture, by their habit of creeping over pebbles and 

 coral, and by their usually bright reddish color. Iridescence has been ob- 

 served in the fresh specimens. 



D. 690, 733, Turner's Island reef, July; D. 545, in rock pockets on 

 shore, Agua Verde Bay, Feb.; D. 497, Catalina Bay, near Guaymas, 

 Feb. ; D. 430j, Pond Island, Feb. 



Hypnea Esperi Bory 



Bory, 1829, p. 157; Kutzing, 1849, p. 759; Tab. Phyc. XVIII, tab. 26a- 

 c; B0rgesen, 1920, p. 306, fig. 48. 



This is another small species similar to Hypnea pannosa in size. The 

 habit is less compactly caespitose and more delicately branched through- 

 out ; the branches are cylindrical, longer, more slender, and more attenu- 

 ate than in that species. 



It is not wtW established what Bory's type of Hypnea Esperi really 

 is, but the Gulf plants do correspond to the illustrations of Kutzing and 

 of B0rgesen. The determinations of this species, therefore, vi^herever they 

 occur, must remain uncertain. 



Our specimens, particularly D. 106, agree excellently with Kiitzing's 

 figure and with B0rgesen's description. 



The present record of its occurrence in the Gulf adds to the already 

 wide distribution attributed to Hypnea Esperi in the warmer Pacific : D. 

 106, lower littoral, reef at Turner's Island, Jan.; D. & R. 3396d, on 

 rocks at low-tide mark, Punta San Pedro, near Guaymas, Dec. ; D. 533, 

 in rock pockets, Agua Verde Bay, Feb. 



Hypnea Johnstonii S. & G. 



Setch. & Gard., 1924, p. 758, pi. 23, figs. 19-21, pi. 57. 



This species is well described and illustrated by Setchell and Gardner, 

 and is to be distinguished readily from the other Gulf species by its 

 coarseness and by the absence of an apical cell. The tips have a group of 

 cells instead of one apical initial. 



J. 1 (AHF no. 66), Pond Island, June; J. 125, Tortuga Island, 

 May; D. 494, Catalina Bay, near Guaymas, reef rocks, Feb.; D. 121, reef 

 at Turner's Island, Jan. 



