California Code, Probate Code - PROB § 246

(a) Where a will, trust, or other instrument calls for property to be distributed or taken “in the manner provided in Section 246 of the Probate Code,” the property to be distributed shall be divided into as many equal shares as there are living children of the designated ancestor, if any, and deceased children who leave issue then living.  Each living child of the designated ancestor is allocated one share, and the share of each deceased child who leaves issue then living is divided in the same manner.

(b) Unless the will, trust, or other instrument expressly provides otherwise, if an instrument executed on or after January 1, 1986, calls for property to be distributed or taken “per stirpes,” “by representation,” or “by right of representation,” the property shall be distributed in the manner provided in subdivision (a).

(c) If a will, trust, or other instrument executed before January 1, 1986, calls for property to be distributed or taken “per stirpes,” “by representation,” or by “right of representation,” the property shall be distributed in the manner provided in subdivision (a), absent a contrary intent of the transferor.