320 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 3 



slightly tumid, composed of 2-3 rows of cells separated by internodes 

 100-150 fi long; tetrasporangia in whorls, shortly pedicellate and naked 

 but borne in open hemispherical, cortical involucres about 125 fi broad; 

 cystocarps unknown. 



Type: D. 737, among other minute algae scraped from littoral 

 rocks. Turner's Island, July 18, 1940. Herb. AHF no. 55. 



The tetrasporangial characters are distinctive in this species, which 

 is here proposed with some hesitation because of the scantiness of the 

 type material. It is believed, however, that further summer collections 

 in the Gulf will confirm its separation. 



Geramium equisetoides sp. nov. 

 Plate 51, Fig. 1 



Setch. & Gard., 1924, p. 778, pi. 29, figs. 70, 71, as Ceramium sp. 



Frondes 8-15 mm. altae, dichotomo aut raonopodico ramosae, 80-100 \i diam., 

 tantum ad nodos corticatae ; corticatione separata impensio in furcis superis per 

 elongationem internodiorum latiore usque ad circa 200 \i, non-turaida, in ordinibus 

 4-cellularum quibusque, superne inferneque truncata; tetrasporangiis in ramulis 

 terminalibus aut lateralibus, tumidis, plus minusve in toto corticatis, totaliter im- 

 mersis. 



Fronds 8-15 mm. high, dichotomously or monopodially branched, 80- 

 100 ju, in diam.; young sterile apices usually forcipate with conspicuous, 

 basally dividing terminal cells ; older fertile apices nonforcipate ; cortica- 

 tions only at nodes, separated more and more widely in upper forks by 

 elongation of the internodal cells until a maximum of about 200 ju, is 

 reached, nontumid, composed of about 4 rows of cells, truncate below 

 and above; tetraspores in swollen, more or less completely corticated 

 terminal or lateral ramuli, completely immersed, usually in a single 

 whorl at each node; tetrasporangial branches sometimes forked but us- 

 ually simple, the shorter ones resembling the sporiferous shoots (strobili) 

 of Equisetum; cystocarps unknown; antheridia completely covering ter- 

 minal ramuli. 



Type : D. 479, rock-shingle beach and upper sublittoral, Puerto 

 San Carlos, Guaymas, Feb. Herb. AHF no. 56. 



D. 389a, lower littoral, Tepoca Bay, Feb. ; D. 602b, shallow littoral 

 pools, San Gabriel Bay, Espiritu Santo Island, Feb. ; D. 42, growing on 

 Gigartina, Guaymas Harbor, Jan.; D. & R. 3309c, 3149, 3160, littoral, 

 Guaymas Bay, Dec. ; M. 63a, growing on EucheumOj Mazatlan, Mexico, 

 May. 



