BoT.— Vot. II.] NOTT—CALIFORNIAN NITOPHYLLA. 33 



Others the segments are quite broad and very regularly pin- 

 nately arranged. The cause of this variation apparently 

 may be found in the environment. When exposed to vio- 

 lent wave action the fronds become extensively branched. 

 In comparatively quiet waters, on the other hand, the ex- 

 panded frond reaches its widest development. The pre- 

 dominant characteristic of N. andersontauutn is the produc- 

 tion, along the margin of both the prostrate and erect frond, 

 of numerous pinnately arranged, spine-like, minute projec- 

 tions or teeth. The midrib, in its normal state, is the 

 slightly thickened median portion of the frond, due to an 

 increase in size of the cells of the central layer. Unless 

 the frond is stimulated to further growth by injury, the 

 midrib remains in this state, and, on reaching the upper 

 branches of the frond, soon evanesces. Under the process 

 of weathering, however, the margin becomes worn away. 

 This seems to incite the cells of the median portion to 

 renewed growth, with the result that the stalk and definite 

 midrib become thickened and almost cylindrical. This spe- 

 cies does not commonly proliferate. 



The tetrasporangia are as yet the only reproductive 

 structures observed. The antheridia and cystocarps have 

 not, so far as can be learned, been seen in the species. 



It seems to the writer desirable to allow this species to 

 remain under JVitophylliim rather than to assign it to Neiiro- 

 glossum. The habit, sori, and inner structure furnish evi- 

 dence for thus placing it. Since it was first reported from 

 this coast, doubt seems to have existed in the minds of writ- 

 ers as to whether it was a Nitofhyllum or a JVetiroglossum. 

 The synopses already in existence of the genus Nenroglos- 

 stim and of the present species do not at all permit a defi- 

 nite idea to be gained of the internal structure, and widely 

 varying statements exist as to the position of the sori. But 

 the careful study of an extensive range of specimens has 

 served to establish the writer's belief that for the reasons 

 above mentioned the species can be referred to Nitophyllum 

 until a comparison can be made with type specimen^. 



(3) July 28, 1900. 



