Shell small, oval, white; anterior slope strongly convex; posterior slope concave below apex; apex small, of one and one-half whorls, placed about two-thirds of the way down the shell; radial sculpture of approximately 24 primary ribs and numerous secondary ribs which intersect with concentric cords to form square pits; concentric cords become increasingly stronger toward the periphery so that they are of nearly equal strength with the primary axial ribs at the margin; fissure narrow, about one-sixth the length of the anterior slope; anal fasciole laminated, with lamellae about equal in number to the concentric cords; fasciole marked internally by a tiny ridge; interior of shell probably glossy in living specimens; measurements of holotype: length 3.9 mm., width 2.8 mm., height 2.1 mm.; measurements of paratype: length 5.3 mm., width 3.7 mm., height 2.7 mm.

Emarginula velascoensis Shasky, 1961. Small, white, with relatively few radial ribs; sculpture coarsely cancellate. Length, 5.3 mm; width, 3.7 mm; height, 2.7 mm. Angel de la Guarda Island to Cape San Lucas, Gulf of California, in 73 to 550 m.

This species is closest to Emarginula phrixodes Dall, 1927, from the tropical Western Atlantic. E. velascoensis differs in having a longer, narrower fissure, fewer radial ribs, and proportionally fewer lamellae of the anal fasciole. It should be noted, however, that Dall apparently recorded the number of primary axial ribs of a single sagittal diameter, while the number of primary ribs described for E. velascoensis is the total at the circumference.

Type locality: in 40-80 fathoms, off the south¬west end of Isla Montserrate, Gulf of California, Lat. 25°39"N.; Long. lll°05'W., September 1, I960. Ariel Expedition