CREATE TABLE table_170961_2 (official_name VARCHAR2, area_km_2 VARCHAR2)

What is the name of the parish where the area is 508.30?
SELECT COUNT(official_name) FROM table_170961_2 WHERE area_km_2 = "508.30"
SELECT COUNT("official_name") FROM "table_170961_2" WHERE "508.30" = "area_km_2"