The size of the shell of
Conus marchionatus varies between 12 mm and 68 mm. The
spire is depressed and features spiral striae. The shell's coloration is yellowish or light brown, adorned with large, white, rounded triangular spots. Its pattern of coloring closely resembles that of
Conus marmoreus, though it is generally lighter. The shell is easily distinguished by the absence of the coronal of tubercles, which is characteristic of some other cone snail species, and its relatively small size compared to other members of the genus. ==Distribution==