l62 CALIFORNIA ACADEMY OF SCIEI^CES. [Proc. 3D Ser. 



B. — Plants single or somewhat clustered, broadly lanceolate, plaited on 

 the margin, 5-9 cm. long, 1-2 cm. broad, basal stalk very short or none. 

 San Pedro and Pacific Grove, California. 



In external appearance this form is almost undistinguish- 

 able from Endarachnc. 



38. Endarachne J. Ag. 



Eruiarachne J. Ac, Anal. Alg. Cont., Ill, 1896, 26. 



Plant plain, simple, without a rib, composed of three layers of tissue ; 

 the axillary tissue of slender, intertwined, articulate filaments, on each 

 side of this a single row of slightly coherent hypodermal cells, outside of 

 which there is a double layer of small cells, slightly elongated in a longitud- 

 inal direction ; reproducing by plurilocular sporangia scattered over the 

 whole surface of the plant. 



39. Endarachne binghamiae J. Ag. 



Plate XXX, Figs. 6 and 7. 



Endarachne binghamics ]. Ac, 1. c, 27. 



Plant clustered, smooth, olive-brown, 5 cm. to a dcm. or so high, 1-2 cm. 

 broad, obtuse above, tapering below to a very short stalk. 



A single dried specimen of this plant, collected at San 

 Pedro, California, was received from Prof. McClatchie 

 about the time of the publication of Agardh's description; 

 figure 7 was drawn before the publication was received. 

 In external appearance the plant is almost undistinguishable 

 from the broader form of PhyUitis fascia; it is, perhaps, a 

 little thinner and more abruptly contracted at the base. 

 Agardh places it between Scytosiphon and PhyUitis. It has 

 been suggested that perhaps all that has been called Phyl- 

 litis on this coast is really Endarachne. A study of many 

 specimens from Monterey and San Pedro seems to show 

 that PhyUitis is quite abundant and Endarachne is found, 

 so far at least, only on the Southern coast. 



40. Scytosiphon Ag. 



Scytosiphon Ac, Sp. Alg., I, 1823, 160. 



Plant body filiform when young, tubular when mature, composed of two 

 layers of tissue, the outer of small quadrangular cells, the inner layer of thick- 

 walled, vertically elongated, colorless cells. Plurilocular sporangia developed 

 from the cortical layer of cells, covering the whole surface of the plant ; para- 

 physes single celled, oblong-ovate, sometimes wanting. 



