Description of the holotype: - Shell elongate, obconical, thin, glossy. Length 37.0 mm, width 16.3 mm, height of spire 16.2 mm. Body whorl mostly straight in profile view, a little convex near the shoulder, lower part grooved. Aperture narrow. Spire concave, consisting of 9 whorls. Apical angle about 100°. Protoconch 1,5 smooth whorls, diameter abapically 1.1 mm, just before the first postnuclear whorl a few axial growth lines. First postnuclear whorl with about 13 small nodules and two spiral striae. The postnuclear whorls 2-4 have also nodulation and striae, which gradually disappear to the following whorls. Towards the last postnuclear whorl, the spiral striae become less clear. Suture deep. Just below suture there is an irregular formed spiral ridge. Shoulder edge is carinated. Body whorl with microscopic axial and spiral striae. Lower half of dorsal side sculptured with spiral grooves, in which small axial riblets. Outer lip thin (partly broken posteriorly), translucent near the edge. Main colour bluish-white with brown blotches and punctuated brown-white spirals. Apical whorls with irregular brown spots above the suture, on the last whorl there are ten dark brown spots. The adapical sutural ridge is irregularly white and brown. Just below the shoulder is a white area followed by about 25 brown and white punctuated spirals, occasionally with fine brown and white spirals in between. More or less irregular axial brown flames over the whole body whorl. The anterior part of the shell is brown.
Variability. — There is little variation in shape of the shells. The colouration is more variable, dark brown as well as light brown specimens occur, and also the pattern is variable. The number of spiral colour lines varies from 20 to 30.
Etymology. - The name Conus stocki n. sp. is given to honour Prof. Dr. J.H. Stock, upon his retirement from the Institute of Taxonomic Zoology, University of Amsterdam.

There are three species resembling the species here described. They differ as follows: C.
lemniscatus is strongly grooved with a flatter spire. C. milesi Smith, 1887, has a different colour pattern (lack of spiral colour lines), and it has more postnuclear whorls with a strong coronation (cf. Moolenbeek & Coomans, 1986). C. traversianus Smith, 1875, is the closest related taxon. It is more slender, and has spiral grooves on the entire body whorl. Its colour pattern of spiral lines is less dense and it lacks the brown anterior part.

Masirah Island