This is a beautifully executed blue and white Nabeshima bowl.  This ware is characterized by underglaze blue and overglaze enamel.  The kilns were secret and the wares were made as gifts for the shoguns and royalty.  The Nabeshima porcelain from the Edo period (1603-1867) was traditionally UNSIGNED.  This bowl is the traditional SEVEN SUN size, about 8" wide and 1 3/4" deep. This is a family piece, purchased in Japan, 1948-1952 and the condition is very good.  The decoration and enamel is exquisite.