50 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



Boodlea composita (Harv. & Hooker f.) Brand 



Plant green, spongy, matted, filamentous, the filaments rather stiff; 

 axes scattered, mainly erect, below to 210-315 fi diam., the long cells 

 somewhat clavate, branching irregular, above becoming indistinct; lesser 

 axes with shorter cells, percurrent, oppositely branched, the branching in 

 a plane or somewhat irregular; lesser divisions and branchlets entangled, 

 the free end cells blunt, to 70-140 ju, diam., 3-5 diameters long; the branch 

 systems commonly concrescent, attachment commonly being made by 

 tenacular cells 30-50 fi diam. and about as long, the appressed face slightly 

 discoid-expanded and with the membrane margin lobulate. 



Brand 1904, p. 187, pi. 6, figs. 28-35. 



These plants probably come within the variation of the species B. com- 

 posita as discussed in detail by Brand. Collins (1909, p. 367) at first 

 admitted this genus to the West coast flora and then later dismissed the 

 record as an error, in which he was followed by Setchell and Gardner 

 (1920, p. 232). There is no doubt about this Mexican record of the 

 genus, but it may be that with fuller knowledge a specific distinction may 

 be possible, though for the present in the light of the considerable vari- 

 ability of these plants it seems best to retain the name of the most probable 

 known Pacific species. Satisfactory criteria for distinguishing species in 

 this genus seem yet to be established. 



Mexico : Nayarit, common on surf-beaten rocks of I. Maria Magda- 

 lena, Las Tres Marias, no. 39-636, 9 May 1939. 



Boodlea composita, forma 

 Plate 1, Figs. 1, 2 



Plants small, 1-2 cm tall, densely entangled, several axes arising from 

 a common base, with more or less distinct slightly tapering free basal 

 cells 130-150 fx diam., 0.9-1.4 mm long, branched at the first septum or 

 close above it, the main axes to 360 /x diam., forming veins, not remaining 

 very distinct, the branching chiefly opposite, commonly in more than one 

 plane, but locally bilateral, the divisions anastomosing into a plane or 

 tridimensional network, directly or by tenacular cells about 35-80 fx diam. 

 and nearly as long; areolae irregular, small, about 300-900 [x diam.; the 

 lesser veins with cells to about 140-180 /x diam., 180-270 /t long; ultimate 

 cells 90-180 ju, diam., 180-220 /a long, the free ends rounded acute at the 

 tips. 



This plant was at first taken to be a Microdictyon of the section 

 Boodleoides, but the relatively small amount of flat network and the 

 approximation in size of the several parts to Boodlea composita eventually 



