90 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 17 



mm. broad in middle and lower parts, but often irregularly narrowed 

 above or below, compressed with markedly tapered margins, fusiform in 

 transection, progressively narrower above to ultimate segments which 

 may not exceed 750 ju, wide ; ultimate segments with irregular spinose or 

 falcate pinnae ; growing tips subacute, with an apical cell ; internal struc- 

 ture showing a single, large, thick-walled central axial filament 70-90 /i. 

 in diameter surrounded by a core of slender, thick-walled, longitudinal 

 filaments partially and progressively outwardly invading the remaining 

 medullar}^ tissue of pseudoparenchymatous cells 30-70 /i in diameter; 

 cortex of 2-3 layers of small densely pigmented cells, the outermost about 

 5 ft in diameter ; tetrasporangia elongate, 20-25 /x long, irregularly cruci- 

 ately divided by oblique walls, borne in extensive, irregularly shaped 

 nemathecia produced on the surface of the upper segments; cystocarps 

 small, irregularly reniform, embedded, scattered through structurally 

 little-modified segments throughout mature parts of plants, a vague 

 ostiole sometimes distinguishable ; antheridia not seen. 



Type: Holotype not designated, but according to Kylin, 1944, 

 represented by a specimen collected by Mrs. Bingham under number 

 28231 in the Agardh Herbarium, Botanical Museum, Lund University, 

 Sweden. A search for this specimen in July 1950 failed to reveal it. Only 

 a sheet containing figures labeled Leptocladia binghamiae was found. 



Type locality: Santa Barbara, California. 



Mexican distribution: Pacific Baja Calif. — D. 282, (Jan.), 

 D. 5299, (Sept.), Punta Descanso; D. 1117, Bahia de Todos Santos, 

 Apr.; D. 183, Cabo Colnett, Jan.; D. 8738, (Jan.), D. 9673, (Apr.), 

 San Quintin peninsula; D. 8903, (Jan.), D. 1181, (Apr.), Punta Baja; 

 D. 6560, D. 10360, off Punta San Eugenio, Mar., Nov.; Hubbs 46-215, 

 Isia Cedros, Sept. ; D. 9486, Punta Abreojos, Apr. ; D. 9239, Punta Pe- 

 quena. May; D. 7263, Punta Hughes, Isla Magdalena, Mar. All of 

 these collections were obtained either from dredge-hauls or from beach 

 drift. 



The frequency of tetrasporangial plants, the scattered cystocarps in 

 non-swollen segments, and especially the presence of only one large-dia- 

 meter axial filament running through the medulla, mark this plant as 

 distinct from the similar Pikea calif ornica. 



