Description of Holotype: Shell small, sturdy, yellowish white, base elongate-oval, with nearly parallel sides; height about 3/5 the length, apex posterior, directly above the posterior margin of the shell. Anterior slope broadly convex, posterior slope convex below the apex, sides of shell nearly straight. Nucleus minute, turned under the succeeding part of the shell. Sculpture consists of 16 strong primary cords diverging from the apex; secondary cords develop cm the anterior and lateral slopes and reach nearly the strength of the primary cords at the margin; concentric sculpture consists of raised ridges that reach only half the thickness of the primary fibs but form beads at intersections and deep squarish pits. Margin crenulated by rib extensions. The slit is long and narrow, about 1/5 the length of the anterior slope; the lamellae along the fasciole are thickened, equal in number and thickness to the concentric ridges. Interior glossy, dried animal remaining in the shell. Length, 6.8 mm, width, 4.6 mm, height, 4.1 mm (holotype).

Emarginula angusta differs from other Eastern Pacific and Western Atlantic species in having an elongate and narrow basal outline, hence the name, meaning narrow. Other species have a more oval basal outline. In addition, the lamellae of the fasciole in E, angusta are broad and thick, unlike the other species that have thin lamellae.

Type Locality: Off San Felix Island, Chile, 26°20,S, 80°02'W, 170- 160 meters (93-87 fathoms), Anton Bruun, Cruise 17 station 676B, Menzies trawl, 12 July, 1966, 1 specimen.