▁ ▁Category : 1 9 0 0 ▁birth s ▁Category : 1 9 7 8 ▁death s ▁Category : Univers ity ▁of ▁California , ▁Ber keley ▁al umn i ▁Category : J ew ish ▁American ▁mus icians ▁Category : American ▁folk ▁sing ers ▁Category : Col umb ia ▁Records ▁artists ▁Category : S ong writ ers ▁from ▁San ▁Francisco ▁Category : Sing ers ▁from ▁San ▁Francisco ▁Category : American ▁female ▁singer - song writ ers ▁Category : 2 0 th - century ▁American ▁sing ers ▁Category : Activ ists ▁from ▁the ▁San ▁Francisco ▁Bay ▁Area ▁Category : J ew ish ▁folk ▁sing ers ▁Category : American ▁Un itar ian ▁Universal ists ▁Category : American ▁singer - song writ ers ▁Category : American ▁folk ▁guitar ists ▁Category : American ▁bl ues ▁guitar ists ▁Category : American ▁ac oust ic ▁guitar ists ▁Category : 2 0 th - century ▁American ▁guitar ists ▁Category : G uit ar ists ▁from ▁San ▁Francisco ▁Category : 2 0 th - century ▁American ▁women ▁sing ers ▁Category : J ew ish ▁female ▁mus icians <0x0A> </s> ▁P lac od erm i ▁( from ▁the ▁Greek ▁ π λ ά ξ ▁= ▁plate ▁and ▁ δ έ ρ μ α ▁= ▁skin , ▁literally ▁" plate - sk inned ") ▁is ▁a ▁class ▁of ▁arm oured ▁pre histor ic ▁fish , ▁known ▁from ▁foss ils , ▁which ▁lived ▁from ▁the ▁Sil ur ian ▁to ▁the ▁end ▁of ▁the ▁Dev onian ▁period . ▁Their ▁head ▁and ▁thor ax ▁were ▁covered ▁by