| Rostrum | Widely triangular | Narrowly triangular | Narrowly triangular | Widely triangular |
| Anterolateral corner of carapace | Rounded | Pointed | Pointed | Pointed |
| Distal segment of male antennal peduncle extends beyond half of antennal scale | Yes | No | No | Yes |
| Carpopropodus of 3rd to 8th thoracopodal endopods | 4 or 5-segmented | 6 to 8-segmented | 5-segmented | 5 or 6-segmented |
| Basal plate of 1st and 2nd thoracopodal exopods bears a denticle at outer corner | No | No | No | Yes |
| Relative length of proximal to distal segments of 4th male pleopodal exopod (ps/ds) | Less than 5 times (4.5) | More than 7 times (7.3) | Almost equal | More than 6 times (6.6) |
| Relative length of exopod to endopod of 4th male pleopod (ex/en) (setae not included) | Less than twice (1.7) | Less than twice (1.3) | Less than twice (1.5) | More than twice (2.3) |
| Two terminal setae of 4th malepleopodal exopod | Subequal | Subequal | Distinctly unequal | Subequal |
| Telson length to its basal width | 2.5 | 3.1 | 3.5 | 2.5 |
| Number of spines near statocyst of uropod | 3–5 | 4 or 5 | 3–6 | 5–7 |
| Lateral margins near apex | With uniform series of spines, lacking large spines | With distinctly grouped spines | With uniform series of spines, lacking large spines | With slightly grouped spines |
| Geographical distribution | Northeast Pacific (Alaska to California) | Northeast Pacific (Alaska to California) | North Pacific (Kamchatka Peninsula) | Northwest Pacific (East Sea, Korea) |