« Smooth, thin shell, purple-white, stained black, with a reddish summit; with nine whorls of spire sculpted with longitudinal lines, the suture of which is decorated with very wide convex, tuberculate lines. » – A. Risso: Histoire naturelle des principales productions de ’Europe méridionale et particulièrement de celles des environs de Nice et des Alpes Maritimes vol. IV, Paris 1826, p.129. In fact, the summit is not always reddish; it can be of the same colours than the rest of the shell, as in this specimen from Murcia, SE. Spain. 7mm.

The Trochus matonii by Payraudeau is the type-species of the genus. « Some are found which are striped longitudinally brown and white, in their entire extent, or only of this sort in the lower half, the upper being red and white; others entirely stained with red and white, or whose beads are red in the upper whorls, and brown or greenish in the lower ones. The top of the spire is always coral red. » – B. C. Payraudeau: Catalogue descriptif et méthodique des annelides et des mollusques de l’íle de Corse…, Paris 1826, p.126. As noticed supra, the top of the shell is not always coral red.

« Shell of large size for the genus[…], conical, robust. Protoconch seemingly smooth, of ca 1 whorl, 0.21-0.22mm in width. Teleoconch of 6-7 slightly convex whorls. Sculpture of 3-5 minutely granulose little closely set abapical spiral cords with wide interspaces of about the same strength, and peripheral cord evident formed by 1-5 merged cordlets. Interspaces wide with strong prosocline lamellae. Suture incised. Base convex, with 6-9 concentric reddish or brown spiral cords white dotted and regularly spaced, umbilicus closed also in juveniles, covered with a white callus. Aperture quadrangular, with the columellar callus thickened in the middle portion. Interior of the aperture whitish, nacreous. » – Mariottini & al.: “Integrative taxonomy of northeastern Atlantic top-shells of the genus Jujubinus Monterosato, 1884 (Gastropoda, Trochidae, Cantharidinae)”, European Journal of Taxonomy vol. 1044, march 2026, p.18.

The Trochus striatus var. “monterosatoi” Bucquoy, Dautzenberg & Dollfus, 1884: markedly concave whorls, « separated by a very wide and projecting bead. The sculpture consists of decurrent cords that are more grainy on the first whorls than on the last ones; the columella is truncated at the base where a fairly strong denticulation is noted. The coloring is opaque white with black longitudinal flammules which usually confluence two by two on the sutural rim. » – Bucquoy, Dautzenberg & Dollfus: Les mollusques marins du Roussillon t.1, fasc.9, Paris 1884, p.367.

Trochus striatus var. “monterosatoi” is « commonly found in the sponges of the Gulf of Gabès » in Tunisia (B.D.D. p.367). This is the unidentatus of Philippi. Synonyms: africanus, venosus… Above, a specimen from 1m deep, in Posidonia meadow, Kerkennah islands, Gulf of Gabès. 9mm.

« This species is very common in the Gulf of Gabès. It is rather variable: the whorls are sometimes flat, sometimes depressed upwardly; the colouration is made up of black longitudinal lines, sometimes numerous and thin, sometimes large and widely spaced. » – Ph. Dautzenberg: “Liste des coquilles du Golfe de Gabès”, Journal de conchyyliologie vol. XXXI, Paris 1883, p.307.

This morphotype, whose range seems restricted to the marine transgression of Gabès Gulf, has a « light shell, ivory-whitish background with dark-brown to brown-reddish prosocline elongated flames, 5-8 weakly to minutely granulose spiral cords of varying size, base with 7-10 spiral cords with brown-reddish lines, and a very strong notch on the columella. » – Mariottini & al.: op. cit. p.19.

« Shell thick, variegated in white, red and brownish; eight whorls of spire, sculpted at their base with a very wide convex, nippled line, with the interstices lined with tuberculate longitudinal lines; the two apical whorl nippled. […] Regions of algae. » – A. Risso: Histoire naturelle des principales productions de l’Europe méridionale et particulièrement de celles des environs de Nice et des Alpes Maritimes vol. IV, paris 1826, p.127.