The shell is with around 10 mm of medium size, lightweight, fragile and ellipsoid. The spire mostly pronounced and is covered by thin callous and terminal ribs. The body whorl is elliptical, inflated and rounded, about 95% of total height, with the anterior terminal produced and posterior almost obsolete. The terminal tips are barely indented. The dorsum is trapezoid elevated, rounded, completely covered by 26-30 fine and irregular ribs. The ribs are always bisected by a smooth dorsal sulcus. The ventrum is convex, with recurved terminals. The aperture is relatively narrow, widens at the fossular region and almost straight. The labrum is somewhat broad, straight, roundly keeled towards its inner margin, widest in mid-portion, becoming narrower towards the terminals. The outer margin of the lip is slightly to strongly, angularly callused with a rounded ridge on the shoulder. The labrum bears on its inner margin 20-23 fine denticles of equal distance. The anterior portion of the labrum is declive. Most part of the labrum slopes steeply towards the shoulder. The siphonal and anal canals follow the shell profile. The columella is convex, tapering nearly vertically inwards, bearing 19-22 ribs, which continue onto the columella, where they become finer. The fossula is concave and not clearly delimited from the rest of the columella. The inner fossular edge is slightly protruded.
The shell color is reddish superimposed with diffuse brown freckles on the dorsum, with one brown, patch on each side of the sulcus and at the anterior and posterior end of the groove and sometimes two mid-dorsally. The ribbing, the dorsal sulcus, the columella and the fossula are white. A ring of a more intensive shell color encircles the dorsum at the suture of the outer labral margin that becomes more diffuse at the ventral margin. The projection of the spire varies considerably. In some shells the spire is obscured. The outline of the shell varies from somewhat pyriform to elliptical. The blotches are in some shells obsolete.
Holotype: L = 9.3 mm, W - 6.4 mm, D = 5.6

Pusula macaeica nov. sp. unites several features of different genera in itself. The shell morphology, especially the dorsal sulcus and the dorsal patches, remind strongly Ellatrivia memorata (Finlay, 1927) an endemic species of Australian and Tasmanian waters with probably intracapsular development. The reddish ventrum is closely similar to Pusula pullata (Sowerby, 1870) from the Bahama Isls. The freckled dorsum is, however, seen in Pusula pacei (Petuch, 1987), Pusula radians (Lamarck, 1810) and Niveria suffusa (Gray, 1827). The general appearance could also be compared with Pusula maugeriae (Sowerby, 1832) from the Galapagos Archipelago. The new species belongs indeed not to the genus Ellatrivia because the members of that genus were fossil and recent ones are always restricted to the waters of South Australia, Tasmania and New Zealand. Therefore, any resemblance between P. macaeica and E. memorata could be only explained by convergence. The new species differs from all species of the genus Niveria Jousseaume, 1884 by the broad and smooth dorsal sulcus. It resembles somewhat the Angolan Pusula liltvedi (Gofas, 1984) but the latter has a narrow and distinct dorsal sulcus and is of uniformly brownish coloration without any patches or spots. Also the callosities arc brownish but of somewhat lighter colour. P. macaeica could be also compared with the forms of the Pusula pediculus (Linneaus, 1758) species complex but the new species lacks off the strongly restricted dorsal sulcus that is surrounded by the bisected and knob-like thickened dorsal ribs.
The attachment of P. macaeica to the genus Pusula is only provisionally as the broad and smooth sulcus reminds the genus Pusula Jousseaume, 1884 (cf. Fehse, 2002: 10) but the general appearance of the shell is more similar to Niveria suffusa that also occurs at the Brazilian waters.

Macae, Rio de Janeiro State, Brazil; from local fisherman, trawled by shrimp boats at 150 m.