Os´te-o-clasts [Gr. osteon, bone; klao, destroy.]
Os´tra-co-derms [Gr. ostrakon, shell; derma, skin.]
Ovum [Lat. egg.] Female germ-cell; female, encysted, sexual cell.
O-vip´a-rous [Lat. ovum, egg; pairo, produce.] Producing eggs that mature and are hatched outside the body.
Pal´li-um [Gr. mantle.]
Pa-læ-o-lith´ic [Gr. palaios, ancient; lithos, stone.]
Pa-læ-o-zo´ic [Gr. palaios, ancient; zoe, life.]
Pan-do-ri´na mor´um [Gr. Pandora; moron, mulberry.]
Pan-gen´e-sis [Gr. pas, all; genesis, origin.]