Shell solid, slender, average in size for the genus with a porcellaneous texture. Holotype: 15.4 mm in length, 5.5 mm in width. The protoconches of all specimens are eroded, small, have about 2 whorls, are very dark, almost black colored and have quite straight whorls. There are 6 teleoconch whorls, rapidly increasing in size. The body whorl is about or over of the shell length, the aperture well over half the shell length. The suture is shallow and well visible. The sculpture consists of highly raised spiral ribs with a flat area between them which is covered by well visible straight or oblique and numerous axial ribs. Very faint secondary spiral ribs can be observed in the center between two primary spiral ribs, crossing the axial ribs. The top of the primary spiral ribs is set on two flat, not sculptured slopes. The aperture is narrow, very long and the lip is white colored, not thickened but crenulate. In fully adult shells, the columellar area is covered with a transluscent slaze which has a slight thickening on top of the parietal area and which forms a shield towards the siphonal canal, covering the very small fasciole. The 4 columellar folds are oblique and decreasing rapidly towards the siphonal canal. The 2 upper folds are much more pronounced than the lower ones. The siphonal area is well defined by a stronger than other primary spiral cords, set at the height of the lower columellar folds. In fresh specimens, the color is not visible, as the shells are covered with a grey "intratacalx". Cleaned shells are either grey or chocolate brown with a faint pattern, occasionally of paler axial flames. The outer lip is white or cream colored.

The placement of this species in the genus Subcancilla is not yet definitive. See comments under Mitra honkeri n. sp.
This is another striking Subcancilla that has been confused with S. insculpta for many decades.. S. philpoppei n. sp. is easy to distinguish: the overall coloration is either grey or brown, depending probably on the biotope and the population the specimen belongs to. The spiral ridges are quite sharp and covered on top, very often, by a darker brown line. The sculpture between the spiral ribs consists of evenly set axial riblets, with often a very fine spiral line running in their center. In S. insculpta this central secondary spiral line is more pronounced and the sculpture is much more beaded. The spire is a little more concave in shape in S. philpoppei n. sp.

TYPE LOCALITY
The Philippines. Olango Island, near Mactan Island. Cebu.
DISTRIBUTION AND HABITAT
This is a typical mud species that prefers bottoms between 10 and 25 m deep. Especially active at night. Camotes and Bohol Sea. south to Cagayan. Mindanao.