Length to 13 mm (Cyphocaris challengeri 1). Pereonite I produced anteriorly, overlapping head, form changing from cone-like (in first turn in juveniles) to subrectangular or even rounded (Cyphocaris challengeri 2). Eyes large, reniform. CX IV large, with strongly convex anterior margin, covering all coxae I-III. CX V wider than high. ART 2 of P V with posterodistal sword-like tooth, both margins of tooth smooth, length subequal to distal part of P (ART 3-7 combined). In live animals "swords" projecting laterally. Besides sword-like tooth, posterior margin of ART 2 of P V with 2-3 denticles (Cyphocaris challengeri 3). ART 2 of P VI-VII with strongly serrate posterior lobe, broader in P VI than in P VII. Posteroventral corners of epimeral plates I-III produced posteriorly, sharp. Live animals pale-brown.