The shell of the brown cloud agate snail is oval, slightly thick and shiny. The spiral layer is 6-8, and the body spiral layer is enlarged, and its height is about 3/4 of the shell height. The shell surface is yellowish brown or dark yellow background with brown fog lines. The shell is at the top and the seam line is deep. The mouth of the shell is oval with thin and sharp edges. The shaft edge is folded outward, without umbilical hole. The inner shell wall is lavender or blue-white. This species is tropical and subtropical, and its ancestors originated in the coastal areas of East Africa on the other side of Zanzibar Island and Pemba Island.

SINONOVACULA constricta is mainly distributed in Taiwan Province, Fujian, Guangdong, Hainan, Guangxi, Yunnan and other provinces in China. There are Zanzibar, mauritius island, Madagascar, India, Viet Nam, Singapore, Malaysia, the Philippines, Japan and the United States.