Diagnosis: Shell high-conical, base often slightly concave; 2 rows of 9-13 pointed nodules on last whorl, peripheral nodules crossed by 2-3 threads, threads on base not usually nodulose; columella flared at base, but anterior lip usually rounded; grey or black with white to orange nodules. Penial filament more than half total length of penis; single, undivided, copulatory bursa.
Shell: Mature shell height 5.9-17.1 mm. Shape conical to high-conical (H/B = 1.28-1.80; SH = 1.64-2.44); spire whorls lightly rounded, suture not distinct; spire profile almost straight; periphery of last whorl weakly angled; profile of base often slightly concave. Columella short, concave, flared and hollowed at base, anterior lip slightly projecting in juveniles, otherwise rounded; small eroded parietal and pseudumbilical area. Sculpture of last whorl: 2 rows of pointed nodules, at periphery and shoulder, axially aligned in 9-13 (rarely to 15) pairs; entire surface (including base) with 14-21 narrow spiral threads and microstriae, each nodule crossed by 2-3 major threads; basal threads (below peripheral nodules) 4-8, only rarely becoming nodulose . Protoconch 0.28-0.33 mm diameter, 2.7— 2.8 whorls. Colour: black to dark brown (fading to blue-grey), paler at suture and on base, nodules white to orange; aperture dark brown with pale band at base; columella dark brown.

Unequivocal identification requires anatomical or molecular information; those records listed with a query are based on shells alone and confirmation is required. The distribution in the Philippines is poorly known; there is no available material from southern Mindanao; shells from northeastern Mindanao (USNM) may represent this species, but verification is required. The six known localities of sympatry with E. malaccana are those in the Philippines, Sulawesi and Ambon, listed above (three verified by anatomy and DNA, see Reid et al. 2006; the others, Buton and Ambon, by anatomy only; see Range of E. malaccana for further discussion).
This species was first discovered during molecular studies of the E. malaccana group (Will¬iams & Reid 2004). Subsequently it was found that males could be distinguished from almost all others in the group by their elongate penial filament (rarely seen also in Japanese specimens that, from their distribution, are presumably E. cecillei, and females by their single, undivided copulatory bursa. Shells are not diagnostic, although in comparison with E. malaccana and E. austrotrochoides the basal threads are usually slightly finer and not nodulose (compare shells from Kamenti, Sulawesi, with one of E. malaccana from the same locality; but in the Philippines both species have small nodules on the base). The shell of E. wallaceana often has a more 'prickly' appearance than others in the E. malaccana group, owing to its sharp (rather than rounded) nodules. However, this may simply be the result of the tendency (seen also in E. malaccana, E. austrotrochoides and E. cecillei) of shells from limestone substrates to be more strongly sculptured.

Range: Sunda Strait, south coast of Java, Nusa Tenggara, Banda Sea, Moluccas, central Philippines.
Habitat: This species occurs from the uppermost eulittoral to the highest levels of the littoral fringe.