Length 9-20 mm (Phtisica marina 1). Flagellum of ANT I multi-articulate. ANT II with 2 distal ART of peduncle subequal. P I and II with strong subchela. P I with elongate ART 4. P II longer than pereonite II, ART 2 almost equal to pereonite II, without distal processes, palm of subchela with sack-like processes in males (Phtisica marina 3), without in females (Phtisica marina 2); posterior margin of ART 6 with strong, blunt triangular process, situated proximally from palm, separated from it by excavation. P III and IV long, ART 2 especially long, weakly subchelate; palmar margins of ART 6 straight, with 3-4 unpaired spines in males, without in females. P V much shorter than others, anterior margin of ART 6 smooth, without setae. P VI-VII weakly subchelate, palmar margin of ART 6 with proximal sharp, triangular process, 2 additional spines in middle part of margin. Gills narrow, on pereonites III-IV as long as two thirds of ART 2 of P, shorter on pereonite II. Benthopelagic; dwells on bottoms with abundant weeds, sponges and hydroids. Phtisica acaudata, often mentioned in the literature, is a junior synonym of this species (Vasilenko, 1974).