supplementary spines

knowledge base : exist
structure : inner wall
Stipules : None
Carcass perforations: inner wall (IW) : isn't included in the term
Carcass external plates: inner carcass wall (IW) : Present ; None (external plates and/or inner wall)
Type of carcass external plates (IW) : Spines
Shape of carcass external plates (IW) : isn't included in the term
Direction of carcass external plates (IW) : isn't included in the term
Type of morphological tubes (IW) : None
Additional sheath : isn't included in the term