Shell to 62.0 mm in length, elongate-ovate or fusiform-elongate, very solid, sutures weakly impressed, teleoconch of 7-9 convex whorls, proto-conch of 2.5-3.0 glassy-brown, smooth embryonic whorls. Sculptured with close-set axial and spiral grooves which produce rows of squarish or axially elongated fillets, 3 rows on the post-embryonic whorls, 5-8 rows on the penultimate and 13-19 on the body whorl in addition to 5-7 oblique basal cords; between these main rows of fillets are 1-3 rows of intermediate, slender, latitudinally elongated fillets. Aperture equal in height or longer than the spire, smooth within, outer lip thickened and crimped, columella calloused and with 4-5 prominent folds. Whitish to pale cream in color, ornamented with one or rarely two broad, reddish-brown, central transverse bands on the body whorl and a narrow, ill-defined band adjoining sutures on earlier whorls; this band is often broken up into spots or is absent altogether. The main spiral cords are ornamented with bluish-black dots and dashes, while the intermediate fillets are spotted with reddish-brown, aperture light orange-fawn, deep interior cream.

As N. papilio is the type species for genus Neocancilla, its characteristics define the general char-acteristics of other species in the genus. Subspecies and forms of the nominate species extend the range of variation. In this genus, similarity of the radulae are the most binding characteristic, but, unfortunately are not usually available for individual specimens a collector or scientist is to identify. The description of the genus in Cernohorsky (1991) includes a fairly wide range of characteristics to accommodate the spe¬cies he placed in the genus.


This is moderately wide mitrid (W/L = 0.33 to 0.44 for illustrated specimens) with the spire shorter than the aperture (S/L = 0.37 to 0.50 for illustrated specimens). The spire sides are slightly convex. There are about 6 teleoconch whorls with slightly to moderately convex sides on an adult shell. The sculpture is clathrate with rectangular to square nodes on spiral cords formed by axial, slightly convex riblets separated by fairly narrow grooves crossing slightly convex cords. There are four major spiral cords on the penultimate whorl with one or two narrower cords between them and two convex narrow cords on the shoulders making the suture prominent. Earlier whorls have fewer spiral cords with about 3 on the first teleoconch whorl and with the minor cords not at all prominent. The protoconch is brown to red-brown with convex whorls. On the body whorl in side view on the lip the cords are straight sided with a step at the posterior of major cords and a much smaller step on the minor cords. The fasciole bulges somewhat and has 4 or 5 spiral cords that are narrower toward the anterior and there is a fairly prominent depression between the fasciole and the columellar callus. The outer lip is slightly convex with a fairly gentle convex transition to the anterior canal that produces a prominent dorsal notch. The columellar callus has a raised outer edge from the suture to the anterior tip. There are 4 significant columellar folds. The shell exterior color is usually light cream with black to brown square spots on the spiral cord nodes. Frequently the major cord interstices are brown to red-brown. Some forms of this species give a more black appearance. Spots on nodes coalesce to form larger blotches in spiral bands. The aper¬ture interior and columellar callus are usually orange, but may be yellow.


The animal exterior in general is light grey. In readily visible parts, there are many white blotches in most areas. The siphon exterior posterior of a white band at the tip is light orange-tan to orange-tan with white blotches. Most of the foot sides and top are colored as the siphon base but the orange-tan may be lacking at the posterior. The foot pedestal probably loses color higher on the foot pedestal, fading to light grey. The background color on the tentacle tip is white. The tentacle pedestals are mostly brown to orange-brown. Eyes are black. The proboscis column is colored similarly to the tentacle. Red Sea to Polynesia for the nominate species and Hawaiian Archipelago for N. papilio langfordiana.

This is an easily recognized species which has a subspecies in the Hawaiian Islands. It is so common in certain localities that Garrett (1880) remarked: "At Raiatea (Society Islands), it is so very abundant that I collected about 1,500 specimens in a few days."

Range - From the Red Sea to Polynesia. In sand and weed, intertidal to a depth of 13 m.