Shell elongate conical, slightly fusiform, not constricted at base. Protoconch of 2.5 whorls, regularly tapering to apex; first whorl rather wide, the earlier 0.25 whorl smooth, the following ones with axial ribs extending from suture to suture, and 4 finer spiral cords in the lower half of their intervals; limit from teleoconch ill-defined on 1/4 whorl, marked by development of 2 spiral cords deforming axial ribs. Teleoconch of 11 whorls with straight sides, suture weakly impressed marked from earlier whorls onwards by a fine undulose spiral thread; 2 spiral cords per whorl on the 3 earlier whorls; then a third spiral cord arising at the end of fourth whorl, developing from a fine thread situated between the 2 cords, this third cord remaining weaker than the earlier two except on last whorl. At the beginning of the tenth whorl, a fine spiral thread emerges between the second and third cords, developing into a fourth cord, distinct on last whorl but remaining weaker than the three other ones. A fifth spiral cord, weaker than the fourth one, emerging from suture at base of last whorl, immediately followed by a sixth cord still a little weaker than the fifth one. All these spiral cords with wide undulations, sometimes with slight swelling. The intervals between cords with numerous close-set very fine lamellose axial riblets, and a fine spiral thread on last whorls. Base smooth. Aperture roundly quadrate, anterior canal wide and strongly oblique. Colour plain orange brown.
Size: maximum height 7.6 mm; width at base 1.9 mm; height of protoconch 0.56 mm; width of protoconch 0.43 mm.

This species resembles the preceeding one (Seila chenui n.sp.) in that its teleoconch bears spiral cords with distinct undulations, and differs from it only in its 2,5 protoconch whorls instead of 6. Both species are provisionally attributed to the genus Seila, though their spiral cords are undulose and occasionally slightly swollen. Some specimens resembling ours have sometimes been identified as Seila laqiteala (Gould, 1861) (type locality China Seas) but Gould did not describe the protoconch of his species, and the figure given by Johnson shows a shell broken at both ends, bearing 3 spiral cords per whorl, unequal, smooth, neither undulose nor swollen. A lot labelled Seila laqueata (Gould, 1961) in NMW (lot N° Z. 1955.158.02266 , 2 specimens from Hong-Kong) shows only 3 smooth spiral cords. Our new species differs from Seila crocea Angas, 1878 (type locality NSW, Australia), in its fourth spiral cord and the undulations on the cords; Angas did not describe the protoconch of his species. One specimen labelled Sella crocea in NMW (lot Z.I955.158.02267 ) shows four spiral cords on last whorl, but all of them are smooth without any undulation, and have a colour pattern with scattered white blotches, very different of our species. Our specimens were compared with Seila cinctum Dunker (MNK lot Nr 3237 ); Seila capitata Thiele, 1925 (type locality Agulhas bank) (MNK lot Nr 102723); Seila alfredensis Bartsch, 1915 (type locality Port Alfred, South Africa) (NMW, not material type); and Seila dissimilis Sutter, 1908, type locality New Zealand (NMW, not material type) but all these species differ from ours by their smooth spiral cords instead of regularly undulose or slightly swollen.

Réunion. Found dead in hand-dredged sand at 10-20 m, off Saint-Gilles-les-Bains.