Shell strong, trochoid, of medium-small size (D < 10 mm), spire consisting of 6 1/4 whorls separated by an evident suture. Protoconch cream-white, smooth, of barely one spire whorl and with diameter of 224 pm. Teleoconch consisting of 5 1/4 whorls, covered by oblique growth lines, more evident in the spaces between cords, where 3-5 spiral cords can also be seen. First whorl of light color and 2 or 3 peripheral cords, differing between populations; subsutural cord nodulose in the second whorl. Other cords nearly smooth in many populations and barely nodulose in others. Last whorl with 15-16 .spiral cords. Columella is typical of the subgenus.
Dimensions: Usually between 9 and 13 mm.
Operculum corneous, multispiral, formed by a central nucleus and 8-10 whorls.
Animal according to LUQUE (1984), in the typical specimens, the general body color is light yellow or cream. The head is covered mostly by grayish-brown blotches irregularly dispersed and with two cephalic lappets with fingerlike border; cephalic tentacles elongated and ciliated, dark brown with violet patches; eyes black on short peduncles. Neck lobes with irregular border, the right one has larger extensions than the left one; both show small dots or blotches of yellow or white at their lower face and a sensory organ covered with short papillae at its apex. Epipodial fold with 4 pairs of tentacles, similar to the cephalic ones but shorter and of light color. Between the first and second pairs, and at the base of the 2nd, 3rd and 4th there are sensory organs similar in shape and size to that of the cervical lobe. Large dark brown blotches are at both sides of the foot. Sole rounded in front and blunt at the rear, and it is bordered by papillae. The mantle edge with alternating light and dark grayish bands.
Radula studied from material from L'Ampolla, Tarragona, Spain. The radula is similar to that of C. cruciatus.

Shell solid, globose, whorls convex, sutures simple, non caniculated. Surface bright crossed by spiral belts, non omogeneous, flattened, without granulosity, divided by very thin grooves. Distinction between cruciatus and corallinus is easy owing to tubercles missing. In periumbilical zone there are some plicae. Umbilicus wide and deep. Conformation of external lip and columela is quite similar to C. cruciatus one. As far as juvenile specimens are concerned, it is visible one cord more prominent at the periphery of last whorl. Colouring is rather variable: generally either brown or greenish in colour with little spots white in colour on belts. Pallary (1904) pointed out subspecies debilis, often assuming a rosy colour, around Gabes Gulf. Varieties in colour and in drawing are numerous and this proves its extreme variability. Average measures of adult specimens are around 9-10 mm in diametre.

Mediterranean, Portugal, and northwestern coast of Morocco. PALLARY (1912) mentions the variety glomus in Tangier. It ranges to Mauritania. It is infralittoral living between 0 and 20 m, under rocks, and among calcareous algae and sponges; in the Mediterranean, it is very frequent in rhizomes of Posidonia oceanica.

Habitat: it lives in the presence of calcareous algae and sponges in the upper infralittoral, on stiff substrata. Distribution: it is collected all over the Mediterranean. Rather common, locally plentifully.