Carapace large with well developed sharp-edged shoulder vaults (C. acutimarginata Habitus 1, C. acutimarginata Habitus 3). There is a slight anterior taper. Postero-dorsal corner angle slightly greater than 90 and bare. Sculpture a series of rectangles arranged in parallel rows in the anterior region and along the tops of the rostra. Left asymmetrical gland opens just anterior to the posterior end of the hinge; right asymmetrical gland about one third-height up the posterior margin. A supplementary group of glands alongside the right asymmetrical gland.
Female, first antenna with long dorsal seta, podomeres covered in fine hairs (C. acutimarginata 1). Frontal organ over double length of first antenna; capitulum sinuately pointed, dorsally with long spinules on basal half, and over most of ventral region (C. acutimarginata 2).
Male, first antenna "e" seta armature a double row of 30-34 long pointed spines (C. acutimarginata 6). Second antenna endopodite, the "b" seta with central large tuft of hairs (C. acutimarginata 7). Righthand hook appendage long and recurved with a swollen ridged end.
This species' occurrence in the North Atlantic implies a global uniformity in the faunistic composition of the abyssopelagic ostracod assemblages.
Known from abyssopelagic depths in the North Pacific and North Atlantic, 20°-49°N. Rarity in collections possibly the result of under collection of the depths >2500m where it lives. 1 (R.R.S. Discovery Map).
Holotype male No 1530 Instituta Okeanologii A.N. USSR.
43°47'N 149°56'E, Kuril-Kamchatka Trench, North Pacific; Vityaz Station 5631; date 2nd September 1966; depth 2390m.