The holotype shell measures 12.2 mm in length and has a typical Acteonid shape: much higher than wide, with a round body whorl, and a spire which is considerably smaller than the body whorl. In this case the spire covers about one third of the total length. The protoconch whorls are very small and raised, the 5 spire whorls are slightly convex in shape. The body whorl, covering about 2 / 3 of the total shell length is broad, cylindrical in shape with almost flat sides. The suture is deeply incised, forming almost a small channel. The entire shell is covered by slightly raised and flattened spiral ribs. These become visible on the third whorl. On the dorsal side, the last spiral whorl has 9 small spiral ribs. These small ribs number 28 on the dorsal side of the body whorl. Especially in the center area of the body whorl, the ribs are flattened on top. In this area, the space between the ribs is about equal to the width of the ribs. The entire shell is covered by tiny axial ribs that overrun the spiral ribs. On the body whorl, this results in a lace-like sculpture. These sculptural characteristics refer the species to the genus Punctactaeon. The aperture is big and covers more than half of the total shell height. The outer lip is thin, not thickened and crenulate where the ribs end. The columellar area has a thin and white colored twisted columella, as if a fold wants to be developed. The entire columellar area is paler than the rest of the shell. The overall coloration is a dirty white, but there is a broad pastel orange-pink colored band in the upper part of the whorls. This band starts on the 4th spiral whorl and ends at the aperture. There is a second band of the same coloration on the lower part of the body whorl.

We figured a specimen of this species as "Acteon sieboldii” in the Philippine Marine Mollusks, Volume 4 in 2011. The confusion with A. sieboldii was caused by the very similar pattern of two dark brown/pinkish bands on the body whorl, on the same place in both species: one below the upper suture, and one above the columellar area, at the base of the body whorl. Difference between both species is clear through the sculptural details: A. sieboldii has an almost flat shell with thin spiral grooves. A. magnificus n. sp. has the typical spaced grooves with points or septa as seen in the genus Punctacteon. A. sieboldii is known from Japan south to China and Taiwan. We here figure a Japanese specimen of A. sieboldii and the holotype of the species. Especially this holotype has a pattern that gave rise to the former confusion.

KNOWN MATERIAL AND LOCALITIES
Philippines. Mactan. Punta Engano. In front of Coral Point. Trawled at a depth between 60 and 250 m.
TYPE MATERIAL
Holotype 12.2 mm. (1296688). Coll. PI. Paratype 1 13.8 mm. (1296789). Coll. MNHN, France. Paratype 2 12.7 mm. (1300798). Coll. G.T. Poppe Paratype 3 11.5 mm. (910063). Coll. KBIN, Belgium.
TYPE LOCALITY
The Philippines. Mactan. Punta Engano. Olango Channel side.
DISTRIBUTION AND HABITAT
The Philippines. At present only known from the type locality and three shells from offshore the northern tip of Olango.