▁ ▁Selected ▁bibli ography ▁Grant , ▁U . ▁S ., ▁& ▁H ert lein , ▁L . ▁G . ▁( 1 9 3 8 ). ▁The ▁West ▁American ▁C en oz o ic ▁E ch ino idea . ▁University ▁of ▁California ▁Press . ▁H ert lein , ▁L . ▁G ., ▁& ▁Grant , ▁U . ▁S ., ▁IV . ▁( 1 9 4 4 ). ▁The ▁ge ology ▁and ▁pale ont ology ▁of ▁the ▁marine ▁P li oc ene ▁of ▁San ▁Diego , ▁California . ▁San ▁Diego : ▁San ▁Diego ▁Society ▁of ▁Natural ▁History . ▁H ert lein , ▁L . ▁G ., ▁& ▁Grant , ▁U . ▁S . ▁( 1 9 4 4 ). ▁The ▁C en oz o ic ▁Bra chi op oda ▁of ▁western ▁North ▁America . ▁University ▁of ▁California ▁Press . ▁H ert lein , ▁L . ▁G ., ▁& ▁W . ▁K . ▁Em erson . ▁( 1 9 5 3 ). ▁M oll us ks ▁from ▁C li pp erton ▁Island ▁( E astern ▁Pacific ) ▁with ▁the ▁description ▁of ▁a ▁new ▁species ▁of ▁g ast rop od . ▁Trans actions ▁of ▁the ▁San ▁Diego ▁Society ▁of ▁Natural ▁History ▁vol . ▁ 1 1 , ▁no . ▁ 1 3 , ▁pp . ▁ 3 4 5 - 3 6 4 . ▁ ▁References ▁ ▁Category : 1 8 9 8 ▁birth s ▁Category : 1 9 7 2 ▁death s ▁Category : American ▁mal ac olog ists ▁Category : American ▁pale ont olog ists