The shell is average to large in size for the genus, slender in shape, solidly build and quite thick, with a porcellaneous material as structure. Holotype: 28.6 mm in length, 8.1 mm in width. The protoconches of all types viewed is broken off, but the first whorls are always black colored and we suspect that when intact specimens are collected, that the protoconch whorls will be equally black colored. The teleoconch has 10 whorls, the body whorl is over half of the shell length and the aperture is half of the shell length or smaller. The suture is deeply incised and inside a sutural channel. The sculpture of the shell is magnificent: the whole shell looks as a jewel when viewed by microscope. The very first whorls have only solid smooth spiral ribs, but as the shell grows these become spaced and they are linked to each other by numerous axial ribs. The spiral ribs which are dark red-brown colored on top are a little wavy, but not pearled. On the periphery of the body whorl the interspaces between the spiral ribs are very spaced and V-shaped in the center. Below these spaced ribs are always two or more closely set spiral ribs that end in the upper part of the aperture. When viewing under magnification the interspaces of these ribs, one can see that the axials are again linked with line spiral ribs. The sutural channel is beaded. The aperture is narrow with a crenulate outer lip. The columellar side is white and bears 4 to 6 oblique weak columellar folds. One dark spiral line extends onto the upper columellar tooth in the holotype and some other shells. The siphonal canal is wide. The coloration of the shell is a pure white with orange-brown spiral lines on top of the spiral ribs. This coloration is more pronounced near the suture and on the two closely set spiral ribs below the periphery. Aperture white, first whorls black colored.

I. rufogyratus n. sp. differs from
- S.filaris by the much more slender shell. The spire is higher, the shell is about half as broad and the aperture is much smaller. The spiral ribs in S. filaris are usually beaded, not in S. filaris
- S. praestantissima: By the much smaller size, sharper spire, smaller aperture and especially the narrowing lower half of the body whorl which is almost pointed with a narrow siphonal canal. In S.praestantissima. the aperture is much wider and the siphonal canal much broader, with the pattern on the columellar side going down much lower. The spiral pattern in S. praestantissima is usually much darker, almost black, while golden brown in S. rufogyratus
- S. pugnaxa has a different shape: the body whorl is much bigger than in S. rufogyratus and curved towards the siphonal canal. The aperture is more than half the size of the shell in S. pugnaxa.The pattern is also different: the spiral lines in S. pugnaxa. are widely spaced and thin, not so in S. rufogyratus. which has a "double line" mid-whorl.
- S. salisburyi. Undoubtedly closely related, but this species has a more swollen body whorl and occasionally it is shouldered. The pattern is different: while the double band is sometimes present in the center, the ribs are irregularly colored in general. The siphonal canal is less narrow and the aperture slightly broader. S. rufogyratus has never the irregular concentration in the color of the spiral lines.
- S. shikamai: The pearled spiral lines and the small size distinguish this species at once. The whorls are more convex with a bigger shoulder and a shorter spire.
- S.yagurai has a much bigger shell, almost twice the size, the spiral pattern is not so pronounced: thinner patterned lines, the shells are more shouldered, the spaces between the spiral lines much broader.

TYPE LOCALITY
The Philippines. Palawan. Balabae Island.
DISTRIBUTION AND HABITAT
The shells from Palawan Island have been dived, probably between 20 and 40 m deep. The shells from Mindanao, Cagayan Island were also dredged in shallow water, most probably between 25 and SO m deep. The shells from Siquijor. Aliguay, Panglaoand Balicasag Island all come from deeper water, most probably from between 50 and 150 m deep. So, this species has probably a bathymetric range from 20 to 100 m deep.