The Genus Phyllospadix 417 



ods in the Tertiary. Distinguished later authorities maintain 

 that much of the coast range region is of recent appearance, 

 and that it has undergone great vertical oscillations during re- 

 cent times. The remarkably bold shore of California may be 

 due to the above phase of its geological history. Ten miles 

 off the coast the ocean shows an average depth of 100 fathoms. 

 But from the brink of this narrow submarine terrace, the bot- 

 tom rapidly descends to 2,000 fathoms or more, the 1,000 fath- 

 oms line being on the average only 50 miles offshore. Sub- 

 marine valleys and canons of great depth, testifying to some 

 great subsidence, often cut through the usual terrace- barriers, 

 into the very shore line itself ; such is the case at Monterey 

 Bajr. The bottom temperature 1,000 fathoms off the coast is 

 35° Fahr. , or but little above freezing. The winter surface 

 temperature at the Golden Gate is about 50°, the summer 

 temperature less than 60°. In the most sheltered parts of 

 Monterey Bay, near Monterey, the summer temperature is 

 about 60°, while on the more exposed shores it has been found 

 at times to be below 50°. 



There is no shallow, shelving sea, as along the old and 

 long worn Atlantic slope of the United states, and few long 

 bays or shallow estuaries and sounds, whose temperature is 

 greatly elevated during hot summers or depressed during cold 

 winters, and which easil}' mingle their waters with the open 

 ocean. On the contrary, on a coast rapidly descending to 

 great and cold depths washed by a current from the north, 

 are flung with great force waters of an even but low tempera- 

 ture, lower still, perhaps, in the vicinity of the submarine 

 valleys. Tliese beat upon the coast and upon the littoral 

 plants with great force. Not alone in the furious storms of 

 the rainy season is the whole coast-line subjected to their 

 powerful action, — even during the long, stormless summers, 

 the breakers are undoubtedly greater in size and the move- 

 ment of the water everywhere stronger than on the Atlantic 

 coast in similar weather. 



In these conditions the marine plants of the eastern Pacific 

 seem to revel. Gigantic fucoids, robust red-algse, strong 

 pliant Zosterse, all attain a completer physical development, 



