| Main Ref. | Steiner, G., 1999 |
| Appearance refers to |
| specialized organs | |
| different appearance | |
| different colors | |
| remarks |
| Striking features | |
| Body shape lateral | |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Diagnosis | Shell: very thin, translucent to transparent, slightly curved and slender, expanding gradually. Radula: Rachidian; superior border with three central projections that eroded quickly and absent in the anterior rows; laterals with pronounced head with a prominent primary cusp, one low posterior secondary denticle and one sharp anterior secondary denticle which is followed by a short nodulose ridge; marginals weakly sinusoidal, outer border wider than that adjacent to the laterals. Mantel edges: anterior with short longitudinal slits positioned dorsoventrally and leads posteriorly from the frontal epithelium of the mantel edge and close to form a short tube; posterior mantel edge forms a valve apparatus with a ventral bolster of connective tissue; a ring of large cells with long cilia outside of the valve apparatus; a two to three-fiber ligament runs from between the statocysts and extending posteriorly to attach at the buccal septum; with two pairs of dorsoventral muscles in the abdominal region, a large inner pair and a smaller outer pair. |
| Ease of Identification | likely to be confused with closely related species. |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | |
| Scale rows below lateral line | |
| Scales around caudal peduncle | |
| Barbels | |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | |
| Fins number | |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | |
| Adipose fin |
| Attributes |
| Fins number | |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes |
| spines | |
| soft-rays | |
| Pelvics | Attributes |
| Position | |
| spines | |
| soft-rays |