41 8 Williaiii Russel D^idley 



perhaps, than in an}^ other waters. Possessing the favoring 

 influence of annual uniformity, presumably for an enormous 

 number of years, the apparent rigors of the sea not improba- 

 bly have acted as a stimulus to the races strong enough to 

 enter its theatre of action. Not improbably the plastic or- 

 ganism of Phyllospadix, subject to forces long continued, 

 inflexible, and dynamically great, has not only developed a 

 structural system so resistant and perfect as to welcome these 

 remarkable conditions, but, like the builders of the coral reef, 

 it can no longer thrive except in the surf or within the influ- 

 ence of the titanic movement of the open ocean. 



I am told that the marine deposits in the coast ranges have 

 not been sufficiently studied to enable specialists to outline 

 clearly the conditions prevailing on the east Pacific shores 

 through the Tertiary and the Quaternary. No question like 

 the present one can approach a settlement until the facts ob- 

 tainable from geological sources are recorded. 



On the other hand, it can safely be said that the biological 

 evidence is likely to favor the hypothesis of a very long period 

 of uniformity in temperature and in the character of the 

 ocean shores and currents, if not in the shore lines, along the 

 whole California coast. It is impossible at present to indicate 

 its duration, but it may well have existed from early in the 

 Quaternary, perhaps even from the confines of the Tertiary, 

 down to present times. 



Palo Ai,to, Cai.., 

 Sept., X893. 



CORRECTIONS. 



I). 412, read "Clavaud." 



p. 4i;:, (2mh \\w), mid "collendiyma-like, the cells." 



p. 414, ( 17Mi line), read "illustrate." 

 " (2fi':li line), read "Sauvageau." 



In tiie "E\i)lanati<)n of Plates", under Plate i, D, Plate rr, 



(t. K. L. M. and R., divi.le the figures indicating magnification 

 by 2. 



