http://www.calpotteries.com/faq/

Yes,, these pics are fine !! I am afraid I am no help with this one !! The California potteries are a wide area and markings are no help on many !! Only way to know which pottery made this is to find the company that used this mold and this color and glaze !! A difficult task with so many that made pottery and used California in the name !! There is no California pottery as such !! Even the word Porcelain is no help !!
Is that all that is written ?? It likely had a stick on label that was lost or removed !!