- There is a decoration like the teeth of a comb from back to tail and large decoration bag under neck.
- Long tail which is 2/3 as long as total body length is used for weapon like a switch when they are attacked.
- Their occipital region is the teeth of a comb shape and they are classified to a subspecies according to the number of scale line of the trunk.
- They primarily inhabit a steppe, a grassland, a savanna and so on and lay an egg under the ground.
- The shell is middle sized long egg type, an apex is located a little in the front side and not projected.
- Interior part is white , there's wide, projected oyster type hinge ligament receiver in the apex of left shell. In the middle of that a hinge ligament is combined.
- The shell is long egg type which is very narrow at the front part and wide at the rear part. The shell is dark violet and very thin with luster.
- They make a keel at the middle part of the ridge of back and behind of that they are paralleled with a back line.
- The shell is middle-large sized species like circular fan.
- In the left abdomen side of the shell, an axial rib extends especially and form wide projection.
- The shell type is various like a pyramid shape, a cone type and so on.
- They are distributed from temperate zone to tropic zone and the species is various.
- The dorsal part of the body disc has tiger pattern dark-brown spots equally on the yellow ground, the abdomen side is white and the front part of anus is yellowish green.
- They inhabit from coastal sea to a continental shelf of 140m depth and live on mainly shrimps.
- They inhabit relatively coastal shallow sea of sandy bed but migrate to deep sea more or less in winter.
- There is a poison fountain in the thorn of tail and when we are pricked, we feel a severe pain.
- A body disc is very big, a diamond shape and has no tail fin behind dorsal.
- There's a poisonous thorn in a tail.
