Social structure is actually observed (e.g., the seashell) whereas structural form is the generalizations or inferences (e.g., the fibonacci sequence).
Social structure is an arrangement of persons in relationship defined and regulated by institutions.
Social structure is composed simultaneously of schemas, which are virtual, and of resources, which are actual.
Social structure is patterned arrangements of role-sets, status-sets, and status sequences consciously recognized and regularly operative in a given society and closely bound up with legal and political norms and sanctions.
Social structure is a set of ideas about the distribution of power in a society. It tolerates contradictions and ambivalence because it's form is a cultural form. It finds expression in the form of ritual expression.
Social structure is regular, routine patterns of behavior (birth, death, marriage). Cultural systems are systems of symbols by which people understand and direct their lives.
Social structure is composed of contradictory and inconsistent ideas that individuals hold about that system. Individuals are able to do this without embarrassment because of the form in which their ideas are expressed. The form is cultural form... the expression is ritual expression.