- Arms
- Formula: 4>3>2>1.
- Arms I-III with 2 sucker series proximally becoming at least 4 series distally.
- Arms IV with 1-2 zigzag series of suckers.
- Buccal membrane
- Each buccal support with 2 series of suckers.
- Each buccal support with 2 series of suckers.
- Occipital folds
- Three folds present with olfactory organ on first.
- Three folds present with olfactory organ on first.
- Fins
- Do not quite reach anterior margin of mantle.
- Do not quite reach anterior margin of mantle.
- Gladius
- Flat, spoon-like conus present.
Comments
This description is from Naef (1921/23).