NO. 10 DAWSON : MARINE ALGAE, GULF OF CALIFORNIA 305 



Genus BOTRYOGLADIA Kylin 



Botryocladia pseudodichotoma var. datilensis van nov. 



Plate 45, Fig. 7; Plate 73, Fig. 1 



A forma typica, magnitudine prorsus parviore, vesiculis densiore conglobatis 

 divergente; cellularibus glanduliformibus 30-35 \i diam., 5-6 collocatis. 



Plants smaller in size throughout than the species, with more compact 

 arrangement of vesicles ; gland cells 30-35 fi diam., in groups of 5-6. 



Type: D. 116, lower littoral rocks, Turner's Island (El Datil) off 

 south shore of Tiburon Island, Jan. 24, 1940 (tetrasporic). Herb. AHF 

 no. 47. 



In general habit and appearance the specimens on hand resemble the 

 species very strongly. They are, however, smaller in size throughout and 

 show a more compact arrangement of the vesicles. An investigation of the 

 gland cells which B0rgesen has shown to be of specific significance and is 

 here used as a varietal distinction, reveals a difference both in size and ar- 

 rangement. In the typical species they usually measure between 14 and 28 

 ft and are found in large aggregations, up to 25 on a single large interior 

 cell (plate 45, fig. 6). In the Gulf material they are larger, 30-35 ju,, 

 and occur in groups of only 5-6. In view of the great similarities with the 

 Pacific coast species and the not widely separated localities, it seems best 

 to make only a varietal distinction. 



Botryocladia Hancockii sp. nov. 

 Plate 45, Figs. 2-5 



Frondes axibus primariis, solidis, ramosis, vesiculas elongato-saccatas, cavas, 

 plerumque 3 cm. longas, pedicellis teretibus, 2 mm. longis, et in diraidio superno 

 projectionibus secondariis digitiformibus cavis provisas, ferentibus; projectionibus 

 irregularibus et magnitudine variabilus usque ad %-plo longitudine vesicularum 

 primariarum. Specimene typico mesquam complete sed distinguente. 



A single cystocarpic portion known, 3.4 cm. long, consisting of one 

 hollow, saccate branch (or vesicle) subtended by a solid, branched, terete 

 main axis bearing also remnants of 3 other saccate parts ; fronds expand- 

 ing and becoming hollow about 2 mm. from the axil of each branch of the 

 terete axis, the vesicle elongated and bearing a few secondary, hollow, 

 fingerlike projections from the upper half, these irregular and of varying 

 size, up to % the length of the main vesicle ; vesicle-wall consisting of 3 

 cell-layers, the innermost of large cells averaging about 70 by 200 fi, the 

 subcortical layer of cells about 20 by 30 ju, in dimensions, arranged regu- 

 larly over the lateral walls of the large inner cells ; the outer layer of cells 

 incomplete, consisting of small cells 10 ju. or less in diameter, partly cov- 



