Shell large up to 421.5 mm, ventricose, ovate or globose, compressed, thick. Juvenile shell usually elongate becoming globose in adult shells. Position of spire and protoconch is under the excavation or sunken below shoulder of last whorl. Protoconch protrudes above shoulder of last whorl in very young shells. Teleoconch of 2!4-3 whorls. Body whorl shoulder ornamented with row of long and rather slender, straight or curved spines, well separated of 5-9 per whorl, length 14-31 mm. Early growth of spines from half to three quarters of first whorl, terminating in adult shells at outer lip. Apex depressed to concave; protoconch dome-shaped, 3,25-3,75 whorls, finely spirally and radially striated, cream or white, diameter 11.8-13.8 mm, height 6.4-7.5 mm. Radial growth striae rather coarse, crossed with fine spiral striae. Colour pale yellow or whitish with two rows of spiral brown spots intersecting with radial light brown zigzag lines that become reticulate. Colour of adult shells reducing in intensity, from dorsum, becoming whiter towards lip. Aperture wide, semi-circular, posterior outer lip extends upwards, top inverted 'V’ shape. Internal colour pale yellow. Parietal wall and inside aperture glossy. Columella arched, with three or four oblique plaits, fourth weakest. Siphonal canal notch wide and deep, fasciole well defined. Periostracum thin, light brown.

The shell diagnostic features of Melo umbilicatus are its overall compressed appearance with a very wide aperture, a depressed to concave apex, few spines (5-9), posterior outer lip extending upwards with the top inverted 'V shape, and a spire and protoconch in the adult shell which appear sunken below the shoulder of the last whorl. Sometimes M. umbilicatus is confused with M. amphora especially juveniles because they are both elongated and have a protruding protoconch. The apex in M. amphora however, is convex; sharp or has a slightly sharp shoulder crest, the posterior outer lip is relatively flat. The radial streaks are wide and light brown in colour and can be in the form of zigzag lines or solid brown or exhibiting a white marbled pattern. There are three columella plaits. M. aethiopicus by comparison is usually globose in shape and has short and numerous spines (12-18). The measurement of the length of three spines from one fossil specimen of M. umbilicatus from Pasir Ipis, West Java was 14.1-20.3 mm.

Distribution. In Indonesia Melo umbilicatus lives from the southern of Seram Island, Maluku; the islands of the Aru Islands in the Arafura Sea, Maluku; Timika and Fak Fak in West Papua. The distribution of M. umbilicatus outside Indonesia follows Hinton (1977), Bail (1990), Poppe & Goto (1992) and Morrison & Wells (2005) (Fig. 6).
Habitat. On sand or muddy sand from shallow water to a depth of 80 m, taken from dives by fishermen to a depth of 45 m and deep-sea trawling.