92 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



Weeksia howellii Setchell & Gardner 



Setchell & Gardner, 1937, p. 77, pi. 11, figs. 29-30. 



Thallus 20-30 cm. high, membranous, consisting of a single, thin, 

 flaccid, elongated to suborbicular blade with irregular, lobed or laciniate 

 margins, from a negligible stipe attached by a small disc ; medulla com- 

 posed of a network of more or less straight filaments of cells 6-8 ju. in 

 diameter and 8-12 times as long as wide; subcortex of 2-3 layers of more 

 or less angular cells of irregular shape and size, densely filled with gran- 

 ules; cortex of a single layer of slightly radially elongate, more or less 

 conical, pigmented cells; cystocarps generally distributed, deeply em- 

 bedded; carpogonial branches curved, composed of 7-9 cells 10-13 ju, in 

 diameter; tetrasporangia uniformly distributed, not abundant, spherical 

 to subspherical, 18-22 [x in diameter; antheridia unknown. 



Type: Holotype is Howell 89, Aug. 17, 1932, on sheet 236496 in 

 the Herbarium of the California Academy of Sciences, San Francisco, 

 California. 



Type locality: Dredged at Isla Natividad, Baja California, 

 Mexico. 



The original description of Weeksia howellii^ which has merely been 

 rearranged above, is essentially identical with that of W. templetonti 

 except for its indication of a larger plant and of larger carpogonial 

 branch cells. Even the absence of the faint veins of W. templctonii is 

 uncertain, for the description is drawn up from dry material in which 

 the veins would probably be invisible even if present. Clearly, liquid- 

 preserved additional material will be required to verify the identity of 

 this species. 



Gloiosiphoniaceae 



A single species known in the Mexican flora. 

 Gloiosiphonia calif ornica (Farlow) J. G. Agardh 



J. G. Agardh, 1885, p. 10; Smith, 1944, p. 209, pi. 47, fig. 2; Doty, 

 1947, p. 166. Nemastoma calif ornica Farlow, 1877, p. 243; Collins, 

 Holden & Setchell, 1897, no. 397. 



Thalli saxicolous, 4 cm. tall or more, lubricous, consisting of several 

 erect, cylindrical, branched axes from a small discoid attachment; erect 

 axes more or less percurrent, mostly 1.0-1.5 mm. in diameter, with 2- 

 several orders of irregularly multifarious branches, the branches suc- 

 cessively reduced in diameter and slightly narrowed at their bases ; apices 

 attenuate, acute, ending in a single cell; structure consisting in young 



