38 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



depend upon differences in texture, branching, venation 

 and sori. In the foregoing pages an attempt has been 

 made to show the amount of variation possible in these 

 characters, and to emphasize their relative value for spe- 

 cific purposes. The numerous collections made between 

 widely distant limits along the coast at various points and at 

 different seasons of the year, as well as all the available 

 material at hand in herbaria, have failed to yield forms 

 which could not be referred to N. riiprechtiamini as defined 

 in the foregoing account of the species. 



A word with respect to the general shape and segmenta- 

 tion of the frond may be added in regard to the variation 

 existing in N. rufrechtiaiitini. Forms may be found that 

 tend to become elongated, with much prolonged, narrow, and 

 acute segments. Near to these may be placed forms like- 

 wise with the segments prolonged, but flabellately expanded, 

 and with rounded apices. The tendency to expansion is 

 seen to best advantage, finally, in plants that become divided 

 into a few broadly wedge-shaped segments, with these in 

 turn somewhat deeply lobed, with the lobes rounded as in 

 the flabellate type. 



Habitat. — N. ruprechtianuin especially occurs on rocks 

 usually covered with Corallines or Bryozoa and Porifera, 

 among which the prostrate frond attains a rich develop- 

 ment, in deep rock pools on gently sloping shores, littoral 

 to sublittoral zones. 



Distribtition. — Along the coast from San Diego, Califor- 

 nia, northward to Port Orchard, Washington. 



Localities. — San Diego! (D. Cleveland); Point Loma! 

 (Miss Minnie Reed); La Holla! (Miss Minnie Reed); 

 San Pedro! (Mrs. S. P. Monks); Santa Barbara! (Dr. 

 and Mrs. L. M. Dimmick; Mrs. S. P. Cooper); shore of 

 San Luis Obispo County! (Mrs. R. W. Summers); Port 

 Harford! (W. A. Setchell) ; Avila Beach! (Miss Mabel 

 Miles); San Simeon! (E. Palmer); Carmel Bay! (C. P. 

 Nott); Pacific Grove! (M. A. Howe; Mrs. J. M. Weeks; 

 C. P. Nott); Santa Cruz! (Mrs. Boston; C. L. Ander- 

 son; Mrs. J. M. Weeks); DuxburyReef! (W. A. Setchell); 



