14^ SOUTHERN CALIFORNIA ACADEMY OF SCIENCES. 



Rhus dispersa Lesq. ; Table Mountain, Tuolumne County; Pli- 

 ocene. 



Rhus heuUeri Heer ; Corral Hollow, Alameda Count}- ; Miocene. 



Rhus metopioidcs Lesq.; Table Mountain, Tuolumne County; 

 Pliocene. 



RJius mixta Lesq.; Chalk Bluffs, Nevada County; Pliocene. 



Rhus myricaefolia Lesq. ; Chalk Bluffs, Nevada County ; Pliocene- 



Rhus typhinoides Lesq.; Table Mountain, Tuolumne County; 

 Pliocene. 



ZANTHOXII^EAE. 



Zanthoxylon. 

 Zanthoxylon.diversifolhun Lesq.; Nevada County; Pliocene. 



ROSAFLOREAE. 



Cercocarpiis. 

 Cercocarpus antiquus Lesq.; Table JMountain, Tuolumne County; 

 Pliocene. leguminosae. 



Colutea — Bladder-senna. 

 Colutea hozvcniana Lesq. ; Nevada County ; Miocene. 



Li addition to the above named extinct species, a large pro- 

 portion of the plants composing our present flora may be prop- 

 erly considered as, in a measure, prehistoric, for the reason that 

 the majority of them appeared previous to, or about the time of 

 the advent of man. 



California possesses living trees which connect us more 

 closely with prehistoric times than can be claimed by any other 

 region of country on the earth. These have come down to us 

 as living records of an epoch so far distant from the present that, 

 since they germinated and commenced their growth, every other 

 species of the land plants, and the entire mammalian fauna of 

 that epoch have become extinct, and their places occupied by 

 new, and in many instances, widely diff'erent species. 



These "Big Trees" of California open up views and give 

 vivid impressions of the past such as no other living thing can 

 equal, and although their exact ages have not been definitely 

 proven, there seems to be no doubt that some of the individuals 

 now growing on the w-estern slopes of our Sierras are from two 

 to three, or perhaps four, thousand years old. Could these grand 

 old Giants of the Forest portray the changes they have wit- 

 nessed in their lifetime, what grand and fascinating stories they 

 could tell ! 



Prof. C. S. Sargent, in his ''Sylva of North America," says 

 of them : "The average height of Sequoia Wellingtojiiana is 

 about 275 feet, and its trunk diameter near the ground 20 feet, 

 although individuals from 300 to 320 feet tall, with trunks from 



