286 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



Taylor 1930, p. 632, pi. 39 (as Nitophyllum uncinatum) ; Kytin 

 1924, p. 78, fig. 61. 



This species may reach a height of 8 cm and the branches a width of 

 6 mm, but none were so luxuriant in the Point Hughes material, which 

 was sterile. 



Mexico: Baja California, dredged off Point Hughes on Cabo San 

 Lazaro, no. 34-605, 7 Mar. 1934. 



CRYPTOPLEURA Kutzing, 1843 



Thallus flat, freely branching from the margins; macroscopic veins 

 present but lacking descending rhizoids ; microscopic veins present ; growth 

 not from a single apical cell ; tetrasporangial sori marginal or on marginal 

 proliferations ; cystocarps scattered, the gonimoblasts with terminal spores. 



Cryptopleura lobulifera (J. Agardh) Kylin, ^roAr. 



Kylin 1924, p. 90, figs. 75, 76. 



One specimen of diminutive proportions with a few tetraspores ap- 

 peared to belong to this species, the histological characters in particular 

 agreeing well. 



Mexico: Baja California, dredged off Point Hughes on Cabo San 

 Lazaro, no. 34-600 (tetrasporic), 7 Mar. 1934. 



Dasyaceae 



Plants usually bushy, repeatedly branched, the branches bearing mono- 

 siphonous branched filaments of limited growth which may remain free 

 or be united into a network ; axes in some genera corticated by the devel- 

 opment of a circle of pericentral cells, and also by rhizoidal filaments 

 which grow down from the bases of the branchlets; monosiphonous 

 branched filaments sometimes corticated at the very base, distally termi- 

 nating in colorless hairs; sporangia produced in special branchlets or 

 stichidia, tetrahedral; spermatangia borne in clusters on special lateral 

 branchlets ; four-celled carpogenic branches formed near the bases of the 

 branched filaments, with an auxiliary associated with certain sterile cells 

 formed from the same supporting cell. 



KEY TO GENERA 

 1. Radially branched; tetraspores not covered by the outer cells of 



the stichidium Dasya 



1. Dorsiventrally branched; tetraspores completely enclosed in the 



stichidium Heterosiphonia 



