286 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



compressed or flattened, or occasionally subterete, 0.7-0.9 mm. broad, 

 200-400 IX thick; apices semi-acute, not much attenuated; secondary 

 branchlets polystichous but tending to be distichous, constricted at the 

 base, determinate in growth, mostly 2-5 mm. long, mostly simple, nearly 

 as broad as the bearing axis; transection showing a dense medulla of 

 intertwined, compacted filaments adjoining the subcortex of about 3 

 layers of ovoid cells 12-14 /a in greatest diameter, and a pigmented 

 cortex of ± anticlinally arranged rows of about 3 squarish cells 3.0-3.5 

 fi in diameter; secondary growth of the outer cortex in age amplifying it 

 considerably; tetrasporangia borne in nemathecial sori mainly confined 

 to and covering the determinate secondary branchlets, cruciate, of non- 

 uniform shape, 23-35 fi long, 9-11 fi wide; sexual material not seen. 



Type: Holotype is Dawson 628-40, Feb. 16, 1940, on sheet 31 in 

 HAHF. 



Type locality: Rocky reef, Bahia San Jose del Cabo, Baja 

 California, Mexico. 



Mexican distribution : Baja Calif, del Sur — D. 29-40, dredged, 

 Mar., Bahia Santa Maria, Isla Magdalena, Jan.; D. 3311, 3348, 3369, 

 3411, Nov., D. 6771, Cabeza Ballena. 



The new material from Cabeza Ballena includes some richly 

 developed, mature tetrasporangial specimens, but lacks sexual material. 

 These clearly show the slender proportions, the irregular primary branch- 

 ing, and the usually determinate, ± polystichous, secondary branchlets 

 which are distinctive of this apparently localized species. 



Lobocolax deformans Howe 



Howe 1914, p. 91, pi. 32, fig. A, text figs. 20-39; Kylin 1941, p. 

 13, fig. 4; Smith 1944, p. 248, pi. 57, fig. 4; Taylor 1945, p. 213; 

 Dawson 1945c, p. 66; Doty 1947, p. 174. 



Thalli parasitic ? on species of Zanardinula, the same color or paler 

 than the host, consisting of smooth, convoluted or lobed, wartlike sessile 

 cushions 1-8 mm. broad, 1-4 mm. high, attached by a broad, penetrating 

 base which occupies part of the medullary area of the host, made up of a 

 dense tissue of irregularly shaped but roughly ovoid cells ranging in size 

 from 5 to 25 ju, interspersed among branched filaments of elongate cells ; 

 asexual reproduction said to be by a kind of monospore produced in the 

 cortical region of the cushion; sexual reproduction reported but disput- 

 able. 



